Biomedical subjects
Publications and source records attributed to M E Easley.
Stage 3 adult acquired flatfoot occurs when chronic posterior tibial tendon insufficiency results in fixed hindfoot valgus or fixed forefoot abduction and supination. Nonoperative management results in limited success. Corrective fusion is the treatment of choice. Although a variety of arthrodeses have been employed, triple arthrodesis remains the gold standard.
The current authors retrospectively reviewed 147 lower extremity peripheral nerve procedures in 114 patients (average age, 42 years) with chronic lower extremity neuropathic pain to determine whether surgical treatment based on an empirically derived algorithm could reduce pain and improve function. This algorithm assigns crush, stretch, and chronic transection injuries to treatment with transection and containment. Peripheral nerve stimulation was used in conjunction with transection and containment for patients with more chronic presentations for whom previous transections had been unsuccessful. Patients with adhesive neuralgia underwent revision neurolysis with vein wrapping. Patients with repetitive nerve trauma (overuse) underwent primary or revision neurolysis. Duration of symptoms averaged 37 months, and mechanisms of nerve injury included chronic transection, crush, adhesive neuralgia, stretch, repetitive trauma, and idiopathic etiology. Time to followup averaged 38 months. Pain and dysfunction were ranked from 0 points (no pain or dysfunction) to 10 points (pain prompting request for amputation or functional deficit warranting wheelchair use); preoperative and followup work status were documented. Average pain and dysfunction scores improved: 8.8 to 5.6 points and 7.6 to 5.0 points, respectively. Of the 114 patients, 52 (46%) patients improved their work status, including 35 of 87 (40%) involved in workers' compensation. There were no statistically significant differences in outcome based on mechanism of nerve injury or type of procedure. The consistent average improvement suggests this algorithm assigns the appropriate procedure to a given mechanism of injury.
From 1995 to 1999, the senior author did revision nerve release and vein wrapping (58 limbs in 58 patients) or peripheral nerve stimulation (62 limbs in 62 patients) to relieve intractable lower extremity nerve pain. Vein wrapping was done if the patient had temporary relief after a previous nerve release, if there was evidence of scarring around the nerve, and if nerve pain was triggered by mechanical stimulation. Peripheral nerve stimulation was done when previous nerve operations provided no relief or if the nerve pain was more constant and spontaneous without mechanical provocation. The duration of symptoms preoperatively averaged 52 months, and the number of previous peripheral neurosurgical interventions averaged 2.5. Postoperatively, the average pain improvement was rated as 60% for the patients who had vein wrapping and 41% for the patients who had peripheral nerve stimulation. Of the patients who had vein wrapping, 53% were satisfied, 14% were somewhat satisfied, and 33% were dissatisfied. Of the patients who had peripheral nerve stimulation, 61% were satisfied, 21% were somewhat satisfied, and 18% were dissatisfied. Most patients (78%) stated they would undergo the procedures again.
BACKGROUND: Jones fractures of the fifth metatarsal can be stabilized using intramedullary screw fixation techniques. A range of screw diameters from 4.5 mm to 6.5 mm can be used, but the optimal screw for this procedure has yet to be defined. In clinical practice, we have observed that failure is more likely when smaller diameter screws are used. METHODS: Experimental Jones fractures were created in 23 pairs of human cadaver fifth metatarsals, which were fixed using either 5.0 mm or 6.5 mm screws. Fracture stiffness and pull-out strengths were measured for either screw type and their relationships with bone mineral density and medullary canal diameter were determined. RESULTS: There was no significant difference in the bending stiffness of fractures stabilized with 5.0 mm and 6.5 mm screws; however, different mechanisms of failure were noted for either screw type. Poor thread purchase within the medullary canal was noted with the 5.0 mm screws, while excellent purchase was noted with 6.5 mm screws. Pull-out strength testing revealed significantly higher pullout strengths for the larger 6.5 mm screws. There was no significant difference in bone mineral density or medullary canal diameter between right and left metatarsals. CONCLUSIONS: Fifth metatarsals can often accommodate a 6.5 mm screw for the stabilization of Jones fractures. Larger diameter screws did not result in greater fracture stiffness in our model, but did result in significantly greater pull-out strengths. CLINICAL RELEVANCE: Larger diameter screws may be more appropriate for intramedullary screw fixation of Jones fractures.
This retrospective study analyses the results of subtalar bone block distraction arthrodesis used in the treatment of late complications of calcaneal fractures, acute severely comminuted fractures, nonunion (and malunion) of attempted subtalar arthrodeses, avascular necrosis of the talus, and club-foot deformity. Of 39 patients (41 feet) who had this procedure, 35 (37 feet) returned for follow-up after a mean of 70 months (26 to 140). There were 24 men (25 feet) and 11 women (12 feet) with a mean age of 41 years (16 to 63). Each completed a standardised questionnaire, based on the hindfoot-scoring system of the American Orthopaedic Foot and Ankle Society and were reviewed both clinically and radiologically. Of the 37 operations, 32 (87%) achieved union. The mean hindfoot score (maximum of 94 points) increased from 21.1 points (8 to 46) preoperatively to 68.9 (14 to 82) at the final follow-up. The mean talocalcaneal and calcaneal pitch angles were 20.5 degrees and 4.9 degrees before operation, 25.9 degrees and 8.3 degrees immediately after, and 24.6 degrees and 7.7 degrees at the final follow-up, respectively. The mean talar declination angle improved from 6.5 degrees (-10 to 22) before operation to 24.8 degrees (14 to 32) at the final follow-up. The mean talocalcaneal height increased from 68.7 mm before operation to 74.5 mm immediately after and 73.5 mm at the final follow-up. Of the 37 arthrodeses available for review, 32 were successful; 29 patients (30 arthrodeses) were satisfied with the procedure. Minimal loss of hindfoot alignment occurred when comparing radiographs taken immediately after operation and at final follow-up.
The purpose of the current study was to review results of primary constrained condylar knee arthroplasty in elderly patients with genu valgum deformity. The hypotheses were: (1) constraint has no adverse effects in elderly patients; (2) treating deformity with a constrained condylar knee prosthesis in lieu of lateral ligament release avoids morbidity, particularly peroneal nerve palsy and flexion instability; and (3) press-fit noncemented stem extensions enhance fixation of the cemented core components and are not prone to loosening. Between 1988 and 1993, 44 consecutive primary Constrained Condylar Knee prostheses were implanted in 37 patients (average age, 72.7 years) with an average valgus angle of 17.6 degrees. Indications for the Constrained Condylar Knee implant were: elderly patients with genu valgum deformity and medial collateral ligament incompetence. Outcome was assessed prospectively using the Hospital for Special Surgery and Knee Society scoring systems; followup was by independent observer. Clinical and radiographic followup (average, 7.8 years) was available for 28 knees (26 patients). The Hospital for Special Surgery score improved from 52.2 to 89.6 points. The average Knee Society score and functional scores improved from 27.4 and 32.4 points to 95.2 and 67.2 points, respectively. At followup, the average alignment based on anteroposterior radiographs obtained with the patient weightbearing was 5.3 degrees. No radiographic loosening, prosthetic failures, peroneal nerve palsies, or flexion instability occurred. No failures occurred in the 11 patients (16 knees) who died before the latest followup. To the authors' knowledge, this is the largest reported series with the longest reported followup of patients with primary Constrained Condylar Knee prostheses. The use of the Constrained Condylar Knee prosthesis for elderly patients with low physical demands with genu valgum resulted in significant pain relief and improved function.
Because malunion (usually with dorsal elevation of the first metatarsal) has been reported after the treatment of severe hallux valgus deformities by proximal osteotomies, the current study was designed to compare the sagittal stability of six different metatarsal shaft osteotomies: the proximal crescentic, proximal chevron, Mau, Scarf, Ludloff, and biplanar closing wedge osteotomies. A plate was used in the biplanar closing wedge osteotomy; all others used screws for fixation. Ten fresh-frozen, human anatomic lower extremity specimens were used for each osteotomy. Failure loads were measured as units of force (newtons) and converted to pressure (kilopascals). Then the F-Scan system, which uses a thin insole to measure plantar pressure, was used to evaluate the pressure under the first metatarsal of seven volunteers using four types of shoes. According to the results, in patients with normal bone stock who are compliant, any of the four shoe types tested may be used after a Ludloff, Scarf, biplanar wedge (plantar screw fixation), or Mau osteotomy, but the wedge-based shoe should be used after a proximal crescentic or chevron osteotomy or for patients with severe osteopenic bone.
HYPOTHESIS/PURPOSE: The purpose of this study was to determine the effectiveness of lower extremity peripheral nerve vein wrapping procedures in the management of patients with intractable lower extremity pain. The hypothesis was that nerve insulation through vein wrapping is effective in treating symptoms related to adhesive neuralgia, but not those secondary to intraneural damage. METHODS: We retrospectively reviewed 25 consecutive patients whose intractable chronic lower extremity peripheral neuralgia had been treated with revision neurolysis and vein wrapping. The 14 women and 11 men had an average age of 39 years (range, 21 to 53 years). Vein wrapping was performed using a saphenous vein autograft in 19 patients and a fetal umbilical vein in six patients. The average length of follow-up after vein wrapping was 24 months (range, 12 to 63 months). Assessment of pain and dysfunction was on a scale of 0 (no pain/dysfunction) to 10 (severe enough to prompt request for amputation and required use of a wheelchair). RESULTS: Pain scores improved from a preoperative average of 8.7 points (range, 6 to 10 points) to a postoperative average of 4.6 points (range, 0 to 10 points); dysfunction improved from a preoperative average of 7.3 points (range, 3 to 10 points) to a postoperative average of 4.4 points (range, 0 to 9 points). Although 17/25 patients were satisfied with the procedure, only 14/25 stated they would undergo the surgery again. All eight patients who exhibited no improvement had preoperative and intraoperative evidence of an idiopathic etiology and/or intraneural damage. Preoperatively, 18/25 patients could not work; postoperatively, that number improved to 8/25. CONCLUSIONS: Vein wrapping of lower extremity peripheral nerves is most effective in relieving symptoms related to adhesive neuralgia and less beneficial in the presence of intraneural damage. Although symptoms are rarely relieved completely, vein wrapping typically results in a substantial improvement in symptoms related to scar entrapment of peripheral nerves.
BACKGROUND: The purposes of this retrospective study were to review the results of isolated subtalar arthrodesis in adults and to identify factors influencing the union rate. The hypotheses were that (1) the overall outcome is acceptable but is not as favorable as previously reported, (2) complication rates, especially the nonunion rate, are higher than previously reported, and (3) factors contributing to a less favorable union rate can be identified. METHODS: Between January 1988 and July 1995, 184 consecutive isolated subtalar arthrodeses were performed in 174 adults (115 men and fifty-nine women) whose average age was forty-three years (range, eighteen to seventy-nine years). Eighty patients (46 percent) were smokers. The indications for the procedure included posttraumatic arthritis after a fracture of the calcaneus (109 feet), a fracture of the talus (thirteen feet), or a subtalar dislocation (thirteen feet); primary subtalar arthritis (thirteen feet); failure of a previous subtalar arthrodesis (twenty-eight feet); and residual congenital deformity (eight feet). Rigid internal fixation with one or two screws was used for all feet. Bone graft was used in 145 feet; the types of graft material included cancellous autograft (ninety-four feet), structural autograft (twenty-nine feet), cancellous allograft (seventeen feet), and structural allograft (five feet). Bone graft was not used in the remaining thirty-nine feet. RESULTS: Clinical and radiographic follow-up examinations were performed for 148 (80 percent) of the 184 feet at an average of fifty-one months (range, twenty-four to 130 months) postoperatively. The average ankle-hindfoot score according to the modified scale of the American Orthopaedic Foot and Ankle Society (maximum possible score, 94 points) improved from 24 points preoperatively to 70 points at follow-up. Thirty feet had clinical evidence of nonunion. The union rate was 84 percent (154 of 184) overall, 86 percent (134 of 156) after primary arthrodesis, and 71 percent (twenty of twenty-eight) after revision arthrodesis. The union rate was 92 percent (ninety-three of 101 feet) for nonsmokers and 73 percent (sixty-one of eighty-three feet) for smokers (p < 0.05). Intraoperative inspection revealed that 42 percent (seventy-eight) of the 184 feet had evidence of more than two millimeters of avascular bone at the subtalar joint; all thirty nonunions occurred in this group (p < 0.05). A nonunion occurred in three of the five feet that had been treated with structural allograft and in two of the six feet in which the subtalar arthrodesis had been performed adjacent to the site of a previous ankle arthrodesis. After elimination of the subgroups of feet in patients who smoked, those that had had a failure of a previous subtalar arthrodesis, those that had been treated with a structural graft, and those that had had the subtalar arthrodesis adjacent to the site of a previous ankle arthrodesis, the union rate improved to 96 percent (seventy-three of seventy-six). Complications other than nonunion included prominent hardware requiring screw removal (thirty-six of 184 feet; 20 percent), lateral impingement (fifteen of 148 feet; 10 percent), symptomatic valgus malalignment (five of 148 feet; 3 percent), symptomatic varus malalignment (four of 148 feet; 3 percent), and infection (five of 184 feet; 3 percent). CONCLUSIONS: To the best of our knowledge, the present study includes the largest reported series of isolated subtalar arthrodeses in adults. Our results suggest that the outcome following isolated subtalar arthrodesis is not as favorable as has been reported in previous studies. The rate of union was significantly diminished by smoking, the presence of more than two millimeters of avascular bone at the arthrodesis site, and the failure of a previous subtalar arthrodesis (p < 0.05 for all). Other factors that probably affect the union rate include the use of structural allograft and performance of the arthrodesis adjac
BACKGROUND: The chevron osteotomy, an accepted method for the correction of mild and moderate hallux valgus, is generally advocated for patients younger than the age of fifty years. The purposes of this prospective study were to compare the short-term (two-year) and intermediate-term (five-year) results of this operation with respect to patient satisfaction, flexion and extension of the metatarsophalangeal joint, maintenance of correction, and development of arthrosis and to determine whether the effectiveness of the procedure was limited by age. METHODS: Between April 1991 and September 1992, the chevron osteotomy was performed for the treatment of mild-to-moderate hallux valgus deformity in sixty-six consecutive feet. Forty-three patients (fifty-seven feet) were available for follow-up at both two and five years postoperatively. The two-year and five-year clinical assessments were based on the American Orthopaedic Foot and Ankle Society's hallux-metatarsophalangeal-interphalangeal scale. RESULTS: Between the two-year and five-year follow-up evaluations, there was only a minimal change in overall patient satisfaction, and the average score on the hallux-metatarsophalangeal-interphalangeal scale was unchanged. The passive range of motion of the first metatarsophalangeal joint decreased between the preoperative assessment and the two-year follow-up evaluation and was unchanged at the five-year follow-up evaluation. Radiographic evaluation showed no changes in the hallux valgus or intermetatarsal angle between the two-year and five-year evaluations, although the number of feet with arthrosis of the metatarsophalangeal joint increased slightly, from eight to eleven. Patients aged fifty years or older did as well as younger patients. CONCLUSIONS: At these two follow-up periods, the chevron osteotomy was found to be a reliable procedure for the correction of mild and moderate hallux valgus deformity, and outcome did not differ on the basis of age.
Avascular necrosis of the first metatarsal head is rare. Although idiopathic cases have been reported, AVN of the first metatarsal head is usually iatrogenic following surgical correction of hallux valgus using a distal metatarsal osteotomy with or without lateral soft tissue release. A thorough understanding of the delicate vascular anatomy of the first metatarsal head is essential when surgery is considered. Careful operative technique permits a safe combination of distal osteotomy and lateral soft tissue release. Because the intraosseous blood supply is completely disrupted with distal metatarsal osteotomy, excessive capsular release and saw blade penetration into the lateral capsular vessels must be avoided. Among the thousands of reported distal metatarsal osteotomies performed using a variety of technique modifications of the original procedure described by Austin, the prevalence of AVN is low. Undoubtedly, the first metatarsal head has an excellent capacity to accommodate to changes in its blood supply. Although radiographic changes are frequently observed in the metatarsal head following a distal metatarsal osteotomy with or without lateral release, rarely do these changes progress to symptomatic AVN. These transient radiographic findings probably represent an adjustment period as the metatarsal head recovers from vascular compromise. Not only is AVN of the first metatarsal rare, but it is rare for it to be symptomatic. Many more cases that are never identified may exist. Management of symptomatic AVN of the first metatarsal head has not been standardized because of the infrequency of this condition. Anecdotal experience suggests that simple activity and shoe modifications may suffice; however, joint debridement and metatarsal head decompression may prove beneficial as they have in the management of other joints more commonly afflicted with AVN. Finally, severe head collapse may be salvaged with MTP joint arthrodesis. In the event that a substantial amount of avascular bone must be removed, consideration can be given to bone block distraction arthrodesis to avoid transfer metatarsalgia.
The success of cartilage repair in the ankle and other joints rests on multiple factors. Because native cartilage healing fails to produce hyaline, organized cartilage, the challenge lies in activating an appropriate healing response. The combination of an optimal structural matrix, infusion of pleuripotent cells, and gene-modified tissue engineering to activate an appropriate healing response appears most sensible. Until such technology is available for use in humans, however, autologous chondrocyte transplantation and osteochondral transfer procedures are attractive alternatives.
The surgical treatment of flatfoot deformity has evolved during the past three decades. Soft tissue procedures alone fail to reestablish anatomic bony alignment, and bony procedures alone fail to provide dynamic support to the arch. The goal of any procedure is to reestablish the inherently stable bony configuration with adequate soft tissue balance (tendon transfer) to maintain stability in the dynamic situation. Therefore, a combination of procedures, such as soft tissue procedures combined with calcaneal displacement osteotomies and/or lateral column lengthening, may provide optimal results. The focus of this review is the role of bony correction in the treatment of the adult acquired flatfoot deformity.
Dorsal cheilectomy of the hallux metatarsophalangeal (MTP) joint through a medial approach can effectively provide long-term relief of pain and improve function in symptomatic mild-to-moderate hallux rigidus, despite progression of generalized first MTP joint arthritic degeneration and/or loss of motion. Fifty-seven patients (75 feet) with arthritis of the first MTP joint underwent dorsal cheilectomy through a medial approach for hallux rigidus failing nonoperative management. Excision of the dorsal articular surface of the first metatarsal head and dorsal osteophytes was performed through a medial approach that also allowed for plantar capsular release and removal of lateral osteophytes. Minimum follow-up was 3 years (average, 63 months; range, 37-92 months). Fifty-two patients (68 feet) returned for clinical and radiographic evaluation. American Orthopaedic Foot and Ankle Society Hallux Rating scores improved from a preoperative average of 45 to 85 points at follow-up. Average dorsiflexion improved from 19 degrees to 39 degrees, and the average range of motion improved from 34 degrees to 64 degrees. Preoperative radiographic grade of arthritic degeneration was grade I in 17 feet, grade II in 39 feet, and grade III in 12 feet; at follow-up, the radiographic grade was grade I in 2 feet, grade II in 26 feet, and grade III in 40 feet. Thirty-two feet worsened one grade, 6 feet worsened two grades, and 28 feet demonstrated no change (12 of 28 were grade III, preoperatively). A dorsal spur recurred in 21 feet, 9 of which were symptomatic. Complications included two superficial wound infections and four transient paresthesias of the hallux, all of which resolved uneventfully.
The goal of this study was to characterize Charcot neuroarthropathy of the foot and ankle by specific sites of involvement (ankle, hindfoot, midfoot, and forefoot), modes of presentation, methods of management, and outcome. A summary of treatment and results for 50 ankles, 22 hindfeet, 131 midfeet, and 18 forefeet is presented. Nondisplaced neuropathic ankle fractures typically healed uneventfully with casting and bracing. For displaced ankle fractures, closed reduction and casting generally resulted in loss of reduction and progressive deterioration; better results were obtained with open reduction and internal fixation, using supplemental Kirschner wires and screws. Ankles with Charcot neuroarthropathy and preexisting arthritis typically required arthrodesis. Of the ankles with neuropathic avascular talar necrosis, approximately 1/3 did well with nonoperative intervention and 2/3 required surgery. Chronic, unstable, malaligned Charcot ankles often required arthrodesis. Neuropathic calcaneal fractures were managed successfully nonoperatively. For feet with transverse tarsal joint involvement (Schon Type IV), management was more complex. Nonoperative treatment was successful for less than 1/2. Two thirds of the feet with midtarsus involvement (Schon Types I, II, and III) were managed successfully nonoperatively; 1/3 required surgery for recurrent ulceration, instability, or osteomyelitis. Half of the feet with forefoot neuroarthropathy required surgery for malalignment, ulceration, and/or difficulty with shoewear or braces. This review has established patterns of Charcot involvement of the foot and ankle with corresponding methods of treatment and subsequent responses. From this extensive clinical experience with 221 neuropathic fractures or Charcot joints, recommendations were derived to assist in selecting appropriate management options.
In this study, intermetatarsal angle (IMA) correction, functional outcome, and healing time for the proximal crescentic and proximal chevron osteotomies in moderate to severe hallux valgus deformity were prospectively compared. Seventy-five patients (97 feet) were prospectively randomized to either a proximal crescentic or proximal chevron osteotomy for the correction of moderate to severe hallux valgus deformity with associated metatarsus primus varus. Criteria for study entry included age (adult patients), IMA greater than or equal to 13 degrees, persistent symptoms despite nonoperative treatment, and minimum follow-up of 12 months. Twenty-nine patients (41 feet) in the crescentic group and 37 patients (43 feet) in the chevron group returned for follow-up at an average of 24 and 20 months, respectively. Good results were achieved with both procedures. No statistically significant differences were found with respect to correction of the IMA or to functional outcome between the two groups. Results held true irrespective of patient age, severity of disease, or bilateral involvement. A statistically significant shorter healing time of the first metatarsal was found after proximal chevron osteotomy. Other potential benefits of the chevron procedure included avoidance of dorsiflexion of the first metatarsal, tendency toward less shortening of the first metatarsal, and more medial distribution of tibial sesamoids following surgery, all of which may reduce the potential for development or persistence of transfer lesions.
Mobile-bearing knee arthroplasty (MBKA) has potential advantages compared with conventional fixed-bearing total knee arthroplasty (TKA). By allowing unconstrained axial rotation, MBKA can offer greater articular conformity without an increased probability of loosening due to increased axial torque. Increased articular conformity minimizes polyethylene contact stresses, thereby reducing linear wear and subsurface fatigue failure. Axial rotation of the platform also enables self-correction of tibial component malrotation. Despite these advantages, the long-term clinical results obtained with current MBKA devices are similar to those obtained with well-designed fixed-bearing TKA prostheses, with no data suggesting their superiority. The disadvantages of MBKA include bearing dislocation and breakage, soft-tissue impingement, a steep technique learning curve, and concerns about volumetric wear. Hypothetically, longer-term follow-up of MBKA results may reveal a significant difference from fixed-bearing TKA results as the fatigue failure threshold of incongruent polyethylene is exceeded.
Twenty-two patients with large nonossifying fibromas (NOFs) in weight-bearing bones were studied to evaluate risk of pathologic fracture. Previous reports suggest an absolute size threshold for NOFs beyond which there is a reasonable chance of impending fracture. In this series, 13 (59%) large NOFs had not had pathologic fracture despite exceeding the previously established size threshold. Four of the patients had fractures of the long bone in which the NOF was located without the fracture involving the lesion. In the nine (41%) patients in whom pathologic fracture occurred, healing was uneventful after closed reduction and cast immobilization. Whereas absolute size parameters may be useful in predicting pathologic fracture rate, they do not imply a requirement for prophylactic curettage and bone grafting. The majority of patients with large NOFs can be monitored without surgical intervention, and fractures can be successfully managed with nonoperative treatment.