Daniel C. Farber

Single stage correction with external fixation of the ulcerated foot in individuals with Charcot neuroarthropathy.

The ulcerated foot in individuals with Charcot neuroarthropathy presents a complex problem when correction of the deformity is necessary but the presence of infection precludes the use of internal fixation. We reviewed 11 patients with midfoot Charcot neuroarthropathy, collapse, and ulceration who were at risk for amputation. These patients underwent operative debridement, corrective osteotomy, external skeletal fixation and culture-directed antibiotic therapy as a limb salvage procedure. Patients were transitioned from the external fixator (average 57 days) to total contact casting (average 131 days) and all subsequently progressed to therapeutic footwear in 12 to 49 months of follow-up (average 24 months), except one patient whose medical decline resulted in bedrest. We believe that when performed in properly selected patients, this procedure presents an alternative to amputation and, via corrective osteotomy, results in a shoe-able, functional foot that is potentially less prone to ulceration.

The Mark Coventry Award: Prevention of readmission for venous thromboembolism after total knee arthroplasty.

Venous thromboembolism is the most common reason for readmission after total knee arthroplasty. Prospective contrast venography was conducted from 1984 to 2003 in 1321 patients undergoing total knee arthroplasty. Patients with deep venous thrombosis or pulmonary embolism were treated with warfarin; those with negative venograms received no further anticoagulation. From 1984 to 1992, patients not completing venography were discharged without warfarin; since 1993 patients without venography received warfarin for 6 weeks. Readmission for deep venous thrombosis, pulmonary embolism, or bleeding was tracked for 6 months. Venography was completed in 810 patients; 343 (42.3%) had deep venous thrombosis. Readmission for venous thromboembolism occurred in 0.6% of patients after total knee compared with 1.62% after total hip arthroplasty. Following total knee arthroplasty, patients discharged on warfarin (target INR 2.0) had a 0.21% readmission rate compared with 1.05% for patients with negative venograms discharged without further anticoagulation. One patient suffered a fatal pulmonary embolism after negative venography and no outpatient prophylaxis. Secondary prophylaxis with extended warfarin therapy reduced venous thromboembolism-related readmission. Surveillance venograms were a poor predictor of ultimate thromboembolism risk and need for extended anticoagulation therapy. We therefore recommend extended warfarin prophylaxis for all patients after hospital discharge following total knee arthroplasty. Level of Evidence: Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

The John Charnley Award: prevention of readmission for venous thromboembolic disease after total hip arthroplasty.

Venous thromboembolic disease remains the most common reason for readmission after total hip arthroplasty. Prospective analysis of screening contrast venography was done from 1984 to 2003 in 1972 patients having elective total hip arthroplasty. Patients with deep venous thrombosis or pulmonary embolism received warfarin therapy; those with negative venograms received no further anticoagulation. From 1984 to 1992, patients not completing venography were discharged without warfarin; since 1993, patients without venography received warfarin for 6 weeks. Readmission for deep venous thrombosis, pulmonary embolism, or bleeding was tracked for 6 months. Venograms were completed in 1032 patients; 175 (16.9%) had deep venous thrombosis. Deep venous thrombosis was reduced by a clinical pathway that included continuous epidural anesthesia (14.2% versus 22.5%). The overall readmission rate for venous thromboembolic disease was 1.62%, including 14 pulmonary emboli (three fatal) and 18 femoral deep venous thrombosis. Readmission occurred in 0.27% (1 of 360) patients on continued warfarin, compared with 2.2% (19 of 880) with negative venograms discharged without further anticoagulation. Three patients (0.15%) suffered fatal pulmonary emboli; all had negative venograms and received no outpatient prophylaxis. Extended outpatient warfarin therapy provided effective protection against venous thromboembolic disease readmission. Surveillance venography was a poor predictor of need for continued prophylaxis; all patients should have extended anticoagulation after total hip arthroplasty. Level of Evidence: Therapeutic study, Level I-1 (high-quality randomized trial with statistically significant difference or no statistically significant difference but narrow confidence intervals). See the Guidelines for Authors for a complete description of levels of evidence.

Goniometric Versus Computerized Angle Measurement in Assessing Hallux Valgus

Background: Digital workstations with high-resolution monitors are replacing standard radiographs for image evaluation and interpretation. Radiographic angles in the foot have been evaluated for interobserver and intraobserver reliability with plain films, but use of digital workstations has not been validated. Because the 1-2 intermetatarsal (IM) and hallux valgus (HV) angles help determine the most appropriate bunion procedure, the reliability of these measurements is important. Methods: The HV and 1-2 IM angles were evaluated on preoperative radiographs of 25 patients who subsequently underwent bunion procedures. A standardized technique using a film marker and goniometer on plain film was compared with use of a mouse and computerized angle measurement software at a digital workstation. Three foot and ankle surgeons conducted these measurements at various intervals. Completion of three readings of each radiograph in each format by each observer totaled 1,800 measurements. Results: Computerized measurement gave better overall reliability. For the HV angle, inter-observer agreement (measurements within 2 degrees) improved from 66% with plain films to 81% with the digital workstation (p < 0.001). Intraobserver agreement increased from 72% to 80%. The 1-2 IM angle was similarly reliable with both methods for inter- and intraobserver agreement. Conclusions: This study validates the use of computer-assisted angle measurement on digital radiographs for assessment of HV and 1-2 IM angles. Computerized measurement may result in more reliable readings because it eliminates the error inherent with use of a goniometer and facilitates adjustment of radiographic lines on the computer to ensure correct alignment.

Nonsurgical treatment and early return to activity leads to improved Achilles tendon fatigue mechanics and functional outcomes during early healing in an animal model

Achilles tendon ruptures are common and devastating injuries; however, an optimized treatment and rehabilitation protocol has yet to be defined. Therefore, the objective of this study was to investigate the effects of surgical repair and return to activity on joint function and Achilles tendon properties after 3 weeks of healing. Sprague–Dawley rats (N = 100) received unilateral blunt transection of their Achilles tendon. Animals were then randomized into repaired or non‐repaired treatments, and further randomized into groups that returned to activity after 1 week (RTA1) or after 3 weeks (RTA3) of limb casting in plantarflexion. Limb function, passive joint mechanics, and tendon properties (mechanical, organizational using high frequency ultrasound, histological, and compositional) were evaluated. Results showed that both treatment and return to activity collectively affected limb function, passive joint mechanics, and tendon properties. Functionally, RTA1 animals had increased dorsiflexion ROM and weight bearing of the injured limb compared to RTA3 animals 3‐weeks post‐injury. Such functional improvements in RTA1 tendons were evidenced in their mechanical fatigue properties and increased cross sectional area compared to RTA3 tendons. When RTA1 was coupled with nonsurgical treatment, superior fatigue properties were achieved compared to repaired tendons. No differences in cell shape, cellularity, GAG, collagen type I, or TGF‐β staining were identified between groups, but collagen type III was elevated in RTA3 repaired tendons. The larger tissue area and increased fatigue resistance created in RTA1 tendons may prove critical for optimized outcomes in early Achilles tendon healing following complete rupture.

Correlation between static radiographic measurements and intersegmental angular measurements during gait using a multisegment foot model.

Background: Radiographic examination is a widely used evaluation method in the orthopedic clinic. However, conventional radiography alone does not reflect the dynamic changes between foot and ankle segments during gait. Multiple 3-dimensional multisegment foot models (3D MFMs) have been introduced to evaluate intersegmental motion of the foot. In this study, we evaluated the correlation between static radiographic indices and intersegmental foot motion indices. Methods: One hundred twenty-five females were tested. Static radiographs of full-leg and anteroposterior (AP) and lateral foot views were performed. For hindfoot evaluation, we measured the AP tibiotalar angle (TiTA), talar tilt (TT), calcaneal pitch, lateral tibiocalcaneal angle, and lateral talcocalcaneal angle. For the midfoot segment, naviculocuboid overlap and talonavicular coverage angle were calculated. AP and lateral talo-first metatarsal angles and metatarsal stacking angle (MSA) were measured to assess the forefoot. Hallux valgus angle (HVA) and hallux interphalangeal angle were measured. In gait analysis by 3D MFM, intersegmental angle (ISA) measurements of each segment (hallux, forefoot, hindfoot, arch) were recorded. Results: ISAs at midstance phase were most highly correlated with radiography. Significant correlations were observed between ISA measurements using MFM and static radiographic measurements in the same segment. In the hindfoot, coronal plane ISA was correlated with AP TiTA (P < .001) and TT (P = .018). In the hallux, HVA was strongly correlated with transverse ISA of the hallux (P < .001). Conclusion: The segmental foot motion indices at midstance phase during gait measured by 3D MFM gait analysis were correlated with the conventional radiographic indices. Clinical Relevance: The observed correlation between MFM measurements at midstance phase during gait and static radiographic measurements supports the fundamental basis for the use of MFM in analysis of dynamic motion of foot segment during gait.

Tendon transfers in the treatment of Achilles' tendon disorders.

The Achilles tendon is the strongest tendon in the human body and, as such, has its share of problems. Although many conditions affecting this tendon can be treated nonoperatively, surgical intervention is often necessary. Local, regional, distant, and allograft tendon can be used to supplement or enhance reconstruction or repair of the Achilles tendon. Specific techniques are explored and described and the published results from the literature summarized. This article explores the use of tendon transfers and supplementation in the treatment of insertional and noninsertional Achilles tendinosis as well as in cases of neglected or chronic ruptures of the tendoachilles.

Oxygen tensiometry as a predictor of wound healing in total ankle arthroplasty

OBJECTIVES Total ankle arthroplasty (TAA) typically involves an anterior approach to the ankle that has been shown to have a risk for wound healing problems. We explored the possibility of using oxygen tensiometry as a predictor of incision healing problems in patients undergoing TAA. METHODS The study included 25 patients who underwent TAA with the Scandinavian Total Ankle Replacement (STAR) system at our institution during a three-year period. Transcutaneous oxygen measurements of both ankles were obtained postoperatively to determine whether the results of transcutaneous oxygen tensiometry correlated with wound healing problems. Patients with wound healing problems were compared with those who had an uneventful incision healing. RESULTS Seven patients (28%) had wound healing problems after TAA, and five patients (20%) had early wound erythema. Wound healing problems included delayed healing in five patients and dehiscence in two patients. Three patients had transcutaneous oxygen tension of less than 40 mmHg (a threshold for impaired skin oxygenation) on the operative side, of whom one had healing difficulty whereas two did not. When the threshold was extended to 50 mmHg, seven patients (28%) had low readings, two having wound healing problems. There was no significant difference with respect to oxygen measurements between patients with and without wound healing problems (p=0.3). CONCLUSION Oxygen tensiometry is not thought to be useful for predicting patients at risk for postoperative wound healing complications after TAA, suggesting that, if adequate pulses are present before surgery, the trauma of using excessive superficial traction on the skin during surgery is more responsible for wound healing problems than the underlying blood supply.

Postinjury biomechanics of Achilles tendon vary by sex and hormone status

Achilles tendon ruptures are common injuries. Sex differences are present in mechanical properties of uninjured Achilles tendon, but it remains unknown if these differences extend to tendon healing. We hypothesized that ovariectomized females (OVX) and males would exhibit inferior postinjury tendon properties compared with females. Male, female, and OVX Sprague-Dawley rats (n = 32/group) underwent acclimation and treadmill training before blunt transection of the Achilles tendon midsubstance. Injured hindlimbs were immobilized for 1 wk, followed by gradual return to activity and assessment of active and passive hindlimb function. Animals were euthanized at 3 or 6 wk postinjury to assess tendon structure, mechanics, and composition. Passive ankle stiffness and range of motion were superior in females at 3 wk; however, by 6 wk, passive and active function were similar in males and females but remained inferior in OVX. At 6 wk, female tendons had greater normalized secant modulus, viscoelastic behavior, and laxity compared with males. Normalized secant modulus, cross-sectional area and tendon glycosaminoglycan composition were inferior in OVX compared with females at 6 wk. Total fatigue cycles until tendon failure were similar among groups. Postinjury muscle fiber size was better preserved in females compared with males, and females had greater collagen III at the tendon injury site compared with males at 6 wk. Despite male and female Achilles tendons withstanding similar durations of fatigue loading, early passive hindlimb function and tendon mechanical properties, including secant modulus, suggest superior healing in females. Ovarian hormone loss was associated with inferior Achilles tendon healing.

Temporal Healing of Achilles Tendons After Injury in Rodents Depends on Surgical Treatment and Activity

Introduction: Achilles tendon ruptures affect 15 of 100,000 women and 55 of 100,000 men each year. Controversy continues to exist regarding optimal treatment and rehabilitation protocols. The objective of this study was to investigate the temporal effects of surgical repair and immobilization or activity on Achilles tendon healing and limb function after complete transection in rodents. Methods: Injured tendons were repaired (n = 64) or left nonrepaired (n = 64). The animals in both cohorts were further randomized into groups immobilized in plantar flexion for 1, 3, or 6 weeks that later resumed cage and treadmill activity for 5, 3, or 0 weeks, respectively (n = 36 for each regimen), which were euthanized at 6 weeks after injury, or into groups immobilized for 1 week and then euthanized (n = 20). Results: At 6 weeks after injury, the groups that had 1 week of immobilization and 5 weeks of activity had increased range of motion and decreased ankle joint toe stiffness compared with the groups that had 3 weeks of immobilization and 3 weeks of activity. The groups with 6 weeks of immobilization and no activity period had decreased tendon cross-sectional area but increased tendon echogenicity and collagen alignment. Surgical treatment dramatically decreased fatigue cycles to failure in repaired tendons from groups with 1 week of immobilization and 5 weeks of activity. Normalized comparisons between 1-week and 6-week postinjury data demonstrated that changes in tendon healing properties (area, alignment, and echogenicity) were maximized by 1 week of immobilization and 5 weeks of activity, compared with 6 weeks of immobilization and no activity period. Discussion: This study builds on an earlier study of Achilles tendon fatigue mechanics and functional outcomes during early healing by examining the temporal effects of different immobilization and/or activity regimens after initial postinjury immobilization. Conclusion: This study demonstrates how the temporal postinjury healing response of rodent Achilles tendons depends on both surgical treatment and the timing of immobilization/activity timing. The different pattern of healing and qualities of repaired and nonrepaired tendons suggest that two very different healing processes may occur, depending on the chosen immobilization/activity regimen.