Surgical treatment of the cleft foot

Between 1970 and 1997, we treated a total of 32 cleft feet in 21 patients (11 male and 10 female). We classified cases of cleft foot on the basis of the number of central ray deficiencies. Fourteen patients with 22 cleft feet were followed up for more than 1 year postoperatively (9 feet had no or one central ray deficiency, and 13 feet had two or three central ray deficiencies). The mean follow-up period was 8.8 years. The objective of this study was to evaluate the results of operative treatment of cleft foot. We evaluated the results of three methods: simple closure of the cleft, application of a double-pedicled flap, and insertion of a silicone block. Cosmetic complications, including widening of the foot, hypertrophic scarring, pigmentation of the grafted skin, and overlapping of the toes, were observed in patients with two or three central ray deficiencies. Few functional complications were observed: None of the patients experienced gait disturbances, although one patient complained of pain following walking. Roentgenography showed that the distance between the first and fifth metatarsals was 86 percent of that of the contralateral foot. When treating patients with no or one central ray deficiency, satisfactory results can be expected with simple closure of the cleft. However, in patients with two or three central ray deficiencies, it is difficult to obtain satisfactory results with simple closure of the cleft or application of a double-pedicled flap. Therefore, silicone block insertion to correct the defect is recommended when there is more than one central ray deficiency.     

Heparin-induced Extracorporal LDL precipitation (H.E.L.P) in diabetic foot syndrome - preventive and regenerative potential?

Peripheral arterial disease is more aggressive in concomitant diabetes posing an increased risk for critical limb ischemia and subsequent limb loss. The majority of therapies available are not effective to prevent amputation in patients with severe disease. The current observational study reports the effect of the heparin-induced extracorporal LDL-precipitation (H.E.L.P.) as a novel therapeutic approach in patients with severe diabetic foot syndrome. Seventeen diabetic patients with septic foot lesions recruited from the diabetic outpatient clinic underwent H.E.L.P. apheresis regularly until fibrinogen levels were stabilized at 3 g/l or infection was controllable as evidenced by alleviation of necrosis. Patients were subsequently followed up for 2 to 73 months. Fibrinogen levels were reduced by 68% after H.E.L.P. treatment. No severe complications were noted. Necrosis could be confined in sixteen patients. Minor amputations were indicated in twelve patients. Three patients underwent major amputations of the lower limb and two patients received surgical reconstruction. In conclusion, H.E.L.P. apheresis may offer an alternative therapeutic option to diabetic patients with critically ischemic feet and appears to have a beneficial major/minor amputation ratio.     

Charcot foot in diabetes: farewell to the neurotrophic theory.

Neuropathic osteoarthropathy is characterised by relatively painless swelling together with extensive damage in bones and joints, predominantly in the feet and ankles. The uncontrolled natural course of the condition leads to gross foot deformity, skin pressure ulceration, spreading infections, and sometimes amputation. Jean-Martin Charcot in 1883 described "Charcot foot" named after him in patients with tabes dorsalis insensitivity. Charcot believed that intrinsic bone weakness was the underlying condition, and was caused by neurogenic deficiencies in bone nutrition. His followers believed such dystrophy to be mediated by sympathetic denervation of the bone vasculature (neurotrophic, or neurovascular theory). Attempts to prove this theory were futile. A neurogenic circulatory disorder potentially relevant to bone nutrition could not be identified. Nowadays, Charcot foot is mostly seen in diabetic neuropathy, which has replaced syphilis as a frequent cause of peripheral nerve dysfunction. Recent studies in the diabetic Charcot foot and bone turnover indicate that the neurotrophic theory is a myth. The assumption of bone resorption due to sympathetic denervation proved to be false--sympathetic activity increases osteoclastic activity and thereby bone loss (sympathomimetic bone resorption). Except for the transient, inflammatory stage of the diabetic Charcot foot, there is no evidence of relevant osteoporosis or demineralisation of the foot skeleton in diabetes.     

Single-stage surgical treatment of noninfected diabetic foot ulcers

A retrospective study was undertaken to evaluate a single-stage approach in the treatment of noninfected, chronic, well-perfused diabetic foot wounds. This single-stage approach consisted of total excision of the ulcer with broad exposure, correction of the underlying osseous deformity, and immediate primary closure using a local random flap. Four hundred cases of pedal ulcers were analyzed by chart review. Of those, 67 cases underwent a single-stage surgical treatment and were analyzed for length of hospital stay, postoperative complications, time to heal, recurrence of the ulcer, and postprocedure ambulatory status. The age of the ulcers before surgery was 12 +/- 12 months (mean +/- SD), with a range of 1 to 60. The median perioperative hospital stay was 5 +/- 7.6 days. All patients were followed until the wounds were healed or to amputation. The median total time to heal was 30.8 +/- 40 days. Ninety-seven percent of the wounds healed. The recurrence rate of ulceration was 10.4 percent (seven of 67), over a time span of up to 6 years. All but one patient returned to previous levels of ambulation, and many patients had improved levels of ambulation. The single-stage approach eliminated the need for additional surgical procedures, with their associated costs and risks. In addition, healing times were significantly reduced, resulting in decreased hospital stays and subsequent costs and providing the patient with an expedient return to footwear so that bipedal function could be restored. Most importantly, by addressing the underlying bony pathologic findings, the recurrence rates were also drastically reduced.     

Limb salvage for soft-tissue malignancies of the foot: an evaluation of free-tissue transfer.

Free flaps may safely allow meaningful ambulation, durable limb preservation, and better quality of life in patients undergoing resections of soft-tissue cancers of the foot. To prove this, the records of a series of patients at The University of Texas M. D. Anderson Cancer Center (n = 67) who underwent limb salvage following tumor-related resection (n = 71 procedures) from 1989 to 1999 were retrospectively reviewed. Eighteen patients who were not candidates for local flaps or skin grafts received a total of 20 free flaps to preserve their limbs. Most defects (mean size, 78 cm2; range, 20 to 150 cm2) were on a weight-bearing surface of the foot (nine on a weight-bearing heel, three on a plantar foot); the remainder were on a non-weight-bearing surface (six on dorsum, two on a non-weight-bearing heel). Melanoma was diagnosed in nine cases (50 percent); soft-tissue sarcoma, in seven (39 percent); and squamous cell carcinoma, in two (11 percent). Fasciocutaneous and skin-grafted muscle flaps were used on both weight-bearing and non-weight-bearing surfaces. Free-tissue transfer was successful in 17 of 20 cases (85 percent); the three flap losses occurred in two patients. Minor complications (i.e., small hematoma, partial skin graft loss, and delayed wound healing) occurred in five patients. In all cases of successful free-tissue transfer, patients began partial weight bearing at a mean of 7.4 weeks (range, 2 to 12 weeks), and all ultimately achieved full weight bearing. Sixty-seven percent still required special footwear. In one patient, an ulceration on the weight-bearing portion of the flap resolved after a footwear adjustment. Only one patient was lost to follow-up (mean, 23 months). In the 17 remaining patients, limb salvage succeeded in 15 (88 percent). Of these, nine (60 percent) were alive without evidence of disease, three (20 percent) were alive with disease, and three (20 percent) had died of disease. Local recurrence developed in two patients but was successfully treated by excision and closure. No late amputations were required for local control. Thus, it seems that free flaps help facilitate limb salvage and that they may preserve meaningful limb function in patients who undergo resection of soft-tissue malignancies of the foot.     

Evidence-based antibiotic therapy of diabetic foot infections

In addition to proper cleansing, debridement and local wound care, foot infections in diabetic patients require carefully selected antibiotic therapy. Serious infections necessitate hospitalization for initial parenteral broad-spectrum antibiotic therapy. Appropriately selected patients with mild infections can be treated as outpatients with oral (or even topical) therapy. Initial antibiotic selection is usually empirical, but definitive therapy may be modified based on culture results and the clinical response. Therapy should nearly always be active against staphylococci and streptococci, with broader-spectrum agents indicated if Gram-negative or anaerobic organisms are likely. In infected foot tissues levels of most antibiotics, except fluoroquinolones, are often subtherapeutic. The duration of therapy ranges from a week (for mild soft tissue infections) to over 6 weeks (for osteomyelitis). Recent antibiotic trials have shown that several intravenously or orally administered agents are effective in treating these infections, with no one agent or combination emerging as optimal. Suggested regimens based on the severity of infection are provided.     

The influence of foot position on standing balance

To test the hypothesis that variations in foot position would significantly affect standing balance, we studied ten normal subjects on a Kistler force platform which measured the travel and center of pressure displacement. With the feet together there was substantially more mediolateral (ML) travel than with the axes of the feet 15, 30 or 45 cm apart and the mean ML position of the center of pressure was displaced toward the right; there was no consistent effect on anteroposterior (AP) travel or position. As the right foot was placed 10 and 30 cm forward or back, the least amount of ML and AP travel occurred with the feet even or at 10 cm either direction; the mean AP and ML position moved toward the foot which was placed more posteriorly. Of the five foot angles ranging from toes-out 45 degrees to toes-in 45 degrees, the extent of ML and AP travel was lowest in the toes-out 25 degrees position and greatest in the toes-in 45 degrees position; the mean AP and ML position was farthest forward and to the right with toes-in 45 degrees. These findings have implications for the prosthetic replacement of the lower limbs, sports, ergonomics and postural sway studies.     

Topical hyperbaric oxygen and low energy laser therapy for chronic diabetic foot ulcers resistant to conventional treatment

Chronic foot ulcers are common in long-standing diabetes, may herald severe complications and are often resistant to therapy. To evaluate the effects of adjunctive topical hyperbaric oxygen treatment (THBO) and low energy laser (LEL) irradiation on ulcer healing, a 100 consecutive patients with chronic diabetic foot ulcers (DFU) refractory to 4.5 +/- 1.2 months of comprehensive treatment, were enrolled in a prospective open study. While conventional treatment was continued as necessary, THBO was administered by pumping 100 percent oxygen into a disposable sealed polythylene hyperbaric chamber (150 min x 2 to 3/wk at up to 1.04 atm). Helium-neon LEL irradiation was given concurrently using a Unilaser Scan Unit at 4 J/cm2 for 20 min. Some patients continued THBO at home or their treatment was confined to THBO at home. Patients were monitored every two weeks revealing 81 percent cure after 25 +/- 13 treatments over 3.2 +/- 1.7 months. On follow-up (median 18 months), only 3/81 (4 percent) had reulceration, which responded to THBO/LEL retreatment. Nonresponders had significantly lower ankle brachial indices (ABI) than patients whose ulcers were healed (0.55 vs. 0.78, p < 0.01) and ultimately required amputation. Patient compliance was full and no adverse events occurred. In conclusion, although the study was open and uncontrolled, an 81 percent healing of DFU in patients who previously did not respond to a comprehensive treatment program, constitutes an intriguing preliminary result. Thus, THBO/LEL therapy may be a safe, simple, and inexpensive early adjunctive treatment for patients with chronic diabetic foot ulcers. Our findings should prompt its evaluation by large randomized controlled trials.     

The infected or exposed breast implant: management and treatment strategies

Among the potential complications associated with the use of breast implants are the risks of periprosthetic infection and device extrusion. There is little published information about the effective management of these situations. Conservative recommendations include antibiotic therapy and removal of the implant until resolution of the infection or until the wound has healed. A retrospective review identified patients with periprosthetic infection or threatened or actual device exposure treated by the senior author. Twenty-four patients encompassing 26 affected prostheses were available for review and were classified into seven groups based on initial presentation as follows: group 1, mild infection (n = 8); group 2, severe infection (n = 4); group 3, threatened exposure without infection (n = 3); group 4, threatened exposure with mild infection (n = 3); group 5, threatened exposure with severe infection (n = 1); group 6, actual exposure without clinical infection (n = 5); and group 7, actual exposure with infection (n = 2). To salvage the prosthesis in these patients, various treatment strategies were utilized. All patients with a suspected infection or device exposure were started immediately on appropriate antibiotic therapy (oral antibiotics for mild infections and parenteral antibiotics for severe infections). Salvage methods included one or more of the following: antibiotic therapy, débridement, curettage, pulse lavage, capsulectomy, device exchange, primary closure, and/or flap coverage. Twenty (76.9 percent) of 26 threatened implants with infection or threatened or actual prosthesis exposure were salvaged after aggressive intervention. The presence of severe infection adversely affected the salvage rate in this series. A statistically significant difference exists among those patients without infection or with mild infection only (groups 1, 3, 4, and 6); successful salvage was achieved in 18 (94.7 percent) of 19 patients, whereas only two of seven of those implants with severe infection (groups 2, 5, and 7) were salvaged (p = 0.0017). Ten (90.9 percent) of 11 devices with threatened or actual exposure, not complicated by severe infection (groups 3, 4, and 6), were salvaged. Several treatment strategies were developed for periprosthetic infection and for threatened or actual implant exposure. Patients with infection were placed on oral or intravenous antibiotics; those who responded completely required no further treatment. For persistent mild infection or threatened or actual exposure, operative intervention was required, including some or all of the following steps: implant removal, pocket curettage, partial or total capsulectomy, débridement, site change, placement of a new implant, and/or flap coverage; the menu of options varied with the precise circumstances. No immediate salvage was attempted in five cases, due to either severe infection, nonresponding infection with gross purulence, marginal tissues, or lack of options for healthy tissue coverage. Based on the authors' experience, salvage attempts for periprosthetic infection and prosthesis exposure may be successful, except in cases of overwhelming infection or deficient soft-tissue coverage. Although an attempt at implant salvage may be offered to a patient, device removal and delayed reinsertion will always remain a more conservative and predictable option.     

Leg length preservation with pedicled fillet of foot flaps after traumatic amputations

Six patients with insufficient soft-tissue coverage after lower limb trauma were treated with pedicled fillet of foot flaps to achieve primary stump closure and to preserve leg length. The flaps used were all based on either the posterior tibial neurovascular pedicle, the anterior tibial neurovascular pedicle, or both. Five flaps survived; one patient required conversion of a through-knee to an above-knee amputation and debridement of the flap because of venous thrombosis of the pedicle. In three of the cases, a functional knee joint was preserved. The patients ranged in age from 21 to 54 years, the mean hospital stay was 55.5 days (range, 28 to 76 days), and the mean follow-up time was 14.5 months. Despite an average of 4.3 procedures from initial admission to first discharge and an average of 2.0 postamputation procedures to achieve primary stump healing, all patients have achieved independent mobility with their prosthesis. The advantages of preserving leg length and, where possible, preserving a functional knee joint compensate for repeated procedures on these patients. When planned well, a pedicled fillet of foot flap therefore achieves the aims of amputation, namely, providing primary healing of a sensate, durable, cylindrical stump that is pain-free and preserves maximal leg length. This is achieved with no donor-site morbidity and with no need for microvascular reconstruction.     

Optimal foot shape for a passive dynamic biped

Passive walking dynamics describe the motion of a biped that is able to "walk" down a shallow slope without any actuation or control. Instead, the walker relies on gravitational and inertial effects to propel itself forward, exhibiting a gait quite similar to that of humans. These purely passive models depend on potential energy to overcome the energy lost when the foot impacts the ground. Previous research has demonstrated that energy loss at heel-strike can vary widely for a given speed, depending on the nature of the collision. The point of foot contact with the ground (relative to the hip) can have a significant effect: semi-circular (round) feet soften the impact, resulting in much smaller losses than point-foot walkers. Collisional losses are also lower if a single impulse is broken up into a series of smaller impulses that gradually redirect the velocity of the center of mass rather than a single abrupt impulse. Using this principle, a model was created where foot-strike occurs over two impulses, "heel-strike" and "toe-strike," representative of the initial impact of the heel and the following impact as the ball of the foot strikes the ground. Having two collisions with the flat-foot model did improve efficiency over the point-foot model. Representation of the flat-foot walker as a rimless wheel helped to explain the optimal flat-foot shape, driven by symmetry of the virtual spoke angles. The optimal long period foot shape of the simple passive walking model was not very representative of the human foot shape, although a reasonably anthropometric foot shape was predicted by the short period solution.     

Painful feet in rheumatoid arthritis

Pain in the feet is an important diagnostic feature and a major management problem of rheumatoid arthritis. Of 50 hospitalized patients, 28% recalled painful feet as the sole presenting symptom of their disease.Rheumatoid disease commonly affects the feet: 90% of the patients studied complained of foot pain at some time during the course of their disease, 86% had clinical involvement and 92% had radiological changes in their feet.The forefoot is most frequently involved. Midfoot involvement was noted in 68% but was symptomatic in only 22%. Changes in the ankle were least common but always symptomatic.     

The role of intrinsic muscle flaps of the foot for bone coverage in foot and ankle defects in diabetic and nondiabetic patients

Local muscle flaps, pioneered by Ger in the late 1960s, were extensively used for foot and ankle reconstruction until the late 1970s when, with the evolution of microsurgery, microsurgical free flaps became the reconstructive method of choice. To assess whether the current underuse of local muscle flaps in foot and ankle surgery is justified, the authors identified from the Georgetown Limb Salvage Registry all patients who underwent foot and ankle reconstruction with local muscle flaps and microsurgical free flaps from 1990 through 1998. By protocol, flap coverage was the reconstructive choice for defects with exposed tendons, joints, or bone. Local muscle flaps were selected over free flaps if the defect was small (3 x 6 cm or less) and within reach of the local muscle flap. During the same time frame, the authors performed 45 free flaps (96 percent success rate) in the same areas when the defects were too large or out of reach of local muscle flaps. Thirty-two consecutive patients underwent local muscle flap reconstruction for 19 diabetic wounds and 13 traumatic wounds. All wounds, after debridement, had exposed bone at their base, with osteomyelitis being present in 52 percent of the diabetic wounds and in 70 percent of the nondiabetic wounds. Wounds were located in the hindfoot (47 percent), midfoot (44 percent), and ankle (9 percent). Vascular disease was more prevalent in the diabetic group, in which 42 percent of the affected limbs required revascularization procedures before reconstruction (versus 7 percent in the nondiabetic group). Subsequently, 83 total operations were required to heal the wounds, of which 46 percent were limited to debridement only. Thirty-four pedicled muscle flaps were used: 19 abductor digiti minimi (56 percent), nine abductor hallucis (26 percent), three extensor digitorum brevis (9 percent), two flexor digitorum brevis (6 percent), and one flexor digiti minimi (3 percent). An additional skin graft for complete coverage was required in 18 patients (53 percent). One patient died and one flap developed distal necrosis, for a 96 percent success rate. The complication rate was 26 percent and included patient death, dehiscence, and partial flap or split-thickness skin graft loss. Twenty-nine of the 32 wounds healed. One patient died in the postoperative period; in two others the wounds failed to heal and required below-knee amputations, for an overall limb salvage rate of 91 percent. Diabetes did not significantly affect healing and limb salvage rates. Diabetes, however, did affect healing times (twofold increase), length of stay (2.7 times as long), and long-term survival (63 percent survival in diabetic patients versus 100 percent in the trauma group). Local muscle flaps provide a simpler, less expensive, and successful alternative to microsurgical free flaps for foot and ankle defects that have exposed bone (with or without osteomyelitis), tendon, or joint at their base. Diabetes does not appear to adversely affect the effectiveness of these flaps. Local muscle flaps should remain on the forefront of possible reconstructive options when treating small foot and ankle wounds that have exposed bone, tendon, or joint.     

SUPRACONDYLAR AMPUTATION IN THE AGED

Of 105 consecutive supracondylar amputations done at the San Diego County General Hospital during the five-year period, 1953-58, 88 were in patients more than 60 years of age. Occlusive arterial disease was the reason for operation in 85 of the 88 cases.Presenting complaints at the time of amputation were gangrene in 45 cases, pre-gangrene associated with severe pain in 34. Acute arterial occlusion as a cause of thigh amputation was infrequent.The average age of patients requiring thigh amputation from complications of arteriosclerosis obliterans was 78.3 years; for those with diabetic arteriosclerosis or embolism it was about seven and a half years less.Supracondylar amputation was considered the procedure of choice in the elderly debilitated patients with far-advanced occlusive diffuse arteriosclerosis, complicated by gangrene, ulcer and infection of the toes or feet. Sympathectomy and direct arterial operation if done early in the course of the disease may postpone or prevent subsequent amputation.The surgical mortality rate (first two weeks) for supracondylar amputation was 12.5 per cent. More than two-thirds of the deaths were due to bronchopneumonia.     

Distribution and development of Brugia malayi in reinfected cats.

At various time periods after an initial exposure to 50 Brugia malayi larvae on one hind foot cats were reexposed to an additional 50 larvae in one of 3 ways: on the previously infected limb only, on the contralateral, uninfected limb only, or on both hind limbs simultaneously. At the time of reexposure uninfected controls were exposed to 50 larvae on one hind foot in a similar manner. From 2 to 4 weeks after reexposure to larvae, the cats were necropsied and the appropriate lymph nodes and vessels examined for adult or developing worms. An existing infection in one limb did not influence early migration or development of larvae introduced into the contralateral leg. Previous infection in the same limb did not consistently result in decreases in the number of developing larvae from the second exposure but did alter the distrubution of larvae. In repeat infections, larvae were consistently located in a moe distal area of the limb than were larvae from an initial infection at a comparable time.     

Analysis of the human and ape foot during bipedal standing with implications for the evolution of the foot

The ratio of the power arm (the distance from the heel to the talocrural joint) to the load arm (that from the talocrural joint to the distal head of the metatarsals), or RPL, differs markedly between the human and ape foot. The arches are relatively higher in the human foot in comparison with those in apes. This study evaluates the effect of these two differences on biomechanical effectiveness during bipedal standing, estimating the forces acting across the talocrural and tarsometatarsal joints, and attempts to identify which type of foot is optimal for bipedal standing. A simple model of the foot musculoskeletal system was built to represent the geometric and force relationships in the foot during bipedal standing, and measurements for a variety of human and ape feet applied. The results show that: (1) an RPL of around 40% (as is the case in the human foot) minimizes required muscle force at the talocrural joint; (2) the presence of an high arch in the human foot reduces forces in the plantar musculature and aponeurosis; and (3) the human foot has a lower total of force in joints and muscles than do the ape feet. These results indicate that the proportions of the human foot, and the height of the medial arch are indeed better optimized for bipedal standing than those of apes, further suggesting that their current state is to some extent the product of positive selection for enhanced bipedal standing during the evolution of the foot.     

Salvage after severe lower-extremity trauma: are the outcomes worth the means?

Advances in reconstructive surgery have allowed for impressive salvage after severe lower-extremity trauma but not without complications when compared with immediate below-knee amputation. Several amputation index scores have been developed to help predict successful salvage as defined by a viable rather than a functional extremity. The purpose of this study was to evaluate retrospectively the predictive value of the amputation index scores and to assess prospectively overall health status and specific dysfunction in successful limb salvage and primary and secondary amputation by administering standardized generic and specific outcomes questionnaires (Medical Outcomes Study 36-Item Short-Form Health Survey, Western Ontario and MacMaster Universities Osteoarthritis Index). A retrospective chart review identified 55 severe lower-extremity injuries (Gustilo Type IIIB and IIIC) over a 12-year period (1984 to 1996). Forty-six severe open tibial fractures in 45 patients underwent attempted salvage. All required soft-tissue coverage by either local or free flap or vascular repair for leg salvage. The attempted-salvage group was subdivided into successful salvage and secondary amputation. The other nine patients underwent a primary amputation. There were no statistically significant differences in terms of patient demographics or other injuries (Injury Severity Score) in the three groups. Forty-eight of 54 patients with an average 5-year follow-up completed a validated generic and specific outcomes health questionnaire. In the attempted-salvage group, 89 percent of patients had a successful salvage and 11 percent came to a secondary amputation. The amputation index scores correctly predicted an amputation in 32 percent of patients. The magnitude of the amputation index scores did not correlate with the physical outcomes scores and were not found to add any significant value of information to the surgeon's decision making. Patients undergoing primary and secondary amputation had a worse physical outcomes score (28 versus 38) than successful salvage (p < 0.007). Even so, the SF-36 (physical component score) outcomes score for this group of injured extremities, regardless as to whether salvaged or amputated, was as low as or lower than that of many serious medical illnesses, suggesting that severe lower-extremity trauma impairs health as much as or more than being seriously ill. The mental component score in this group was comparable to that of a healthy population (49 versus 50), which implies the disability is primarily physical rather than psychological. Ninety-two percent of patients preferred their salvaged leg to an amputation at any stage of their injury, and none would have preferred a primary amputation.     

Lower-limb amputee recovery response to an imposed error in mediolateral foot placement

Despite walking with a wider step width, amputees remain 20% more likely to fall than non-amputees. Since mediolateral (ML) balance is critical for ambulation and contingent on ML foot placement, we used a ML disturbance to perturb walking balance and explore the influence of prosthetic foot stiffness on balance recovery. Ten transtibial amputees were fit with two commonly prescribed prosthetic feet with differing stiffness characteristics; 12 non-amputees also participated. A perturbation device that released an air burst just before heel strike imposed a repeatable medial or lateral disturbance in foot placement. After a medial disturbance, the first recovery step width was narrowed (p<0.0001) for the prosthetic limb (−103%), the sound limb (−51%) and non-amputees (−41%) and more than twice as variable. The ML inclination angle remained reduced (−109%) for the prosthetic limb, while the sound limb and non-amputees approached undisturbed levels (p<0.0004). Amputees required five steps to return to undisturbed step width after a prosthetic medial disturbance versus two steps for the sound limb and for non-amputees. After a lateral disturbance, the first recovery step was widened for the prosthetic limb (+82%), sound limb (+75%), and wider than non-amputees (+51%; p<0.0001), with all participants requiring three steps to return to undisturbed step width. Amputees also exhibited a similar upper torso response compared to the non-amputees for both disturbances. Prosthetic feet with different stiffness properties did not have a significant effect. In conclusion, amputee balance was particularly challenged by medial disturbances to the prosthetic limb implying a need for improved interventions that address these balance deficits.     

Shock absorption of below-knee prostheses: a comparison between the SACH and the Multiflex foot

Shock waves were measured during walking on a treadmill on the metal tube of a below-knee KBM prosthesis, provided either with a SACH foot or with a Multiflex foot. Accelerations were measured in the axial direction and the dorso-ventral direction, about 160 mm proximal to the sole of the shoe. The accelerations had comparable amplitudes to those measured on normal legs. Dorso-ventral amplitudes (order of magnitude 4 g) were generally higher than the axial amplitudes. For some patients, the SACH foot gave much higher axial accelerations than the Multiflex foot did. In the dorso-ventral direction, the SACH foot showed a moderate resonance phenomenon in the autospectral density function in the range of 40-50 Hz. The Multiflex foot showed a more variable behaviour. For both types of feet, components above 65 Hz were negligible.     

Ulnar polydactyly

A retrospective review of 148 patients with ulnar polydactyly was conducted to analyze the types, patterns of involvement, associated anomalies, treatments, and outcomes of this malformation. The hands only were involved in 123 patients, both hands and feet in 20 patients, and five patients had mixed radial and ulnar polydactyly. Ulnar polydactyly was more prevalent among males. Among African Americans, the condition was often bilateral. When unilateral, ulnar polydactyly occurred more often on the left side. The racial distribution was 103 African Americans (70 percent), 37 Caucasians (25 percent), four Native Americans, three Latin Americans, and one Asian. Five types were encountered: type I cutaneous nubbin, type II pedunculated digit, type III articulating digit with fifth metacarpal, type IV fully developed digit with sixth metacarpal, and type V polysyndactyly. The distribution of types in order of frequency was type II, III, V, I, and IV. Types I and II ulnar polydactyly combined were more prevalent (82 percent) than types III, IV, and V (18 percent). Types I and II were more common among African Americans. Types III, IV, and V ulnar polydactyly occurred more frequently among Caucasians, but these were slightly less prevalent than types I and II in this racial group. Five patients were syndromic; four were Caucasians, and one Asian. Most cases of ulnar polydactyly of the hand were treated by ligation (71 percent) in the nursery, whereas polydactyly of the foot was more often referred to a specialist to be treated by surgical ablation (92 percent). Treatment complications occurred more frequently in the hands than in the feet. The complication rate after ligation of ulnar polydactyly of the hand was 23.5 percent. The two main complications were tender or unacceptable nubbins and infections.