Bone SPECT/CT in the Evaluation of Painful Total Ankle Replacement: Validation of Localization Scheme and Preliminary Evaluation of Diagnostic Patterns.

PURPOSE: Third-generation total ankle replacement (TAR) is an increasingly popular and effective treatment for end-stage osteoarthritis, yet identifying causes of failure remains challenging. We evaluated integrated bone SPECT/CT in recurrent pain after TAR by validating a standardized reporting scheme, identifying uptake patterns, and assessing diagnostic performance and impact on clinical management. PATIENTS AND METHODS: A total of 24 TARs in 16 patients with persistent or recurrent pain received integrated bone SPECT/CT using diagnostic CT settings. Images were retrospectively reviewed, and a novel localization scheme was validated by assessing interrater agreement. Distinct uptake patterns were identified, and diagnostic test characteristics were estimated. Reference standard consisted of clinical follow-up, laboratory findings, and subsequent procedures, including revision surgery. RESULTS: Standardized scoring of bone SPECT/CT uptake was highly reproducible (intraclass correlation coefficient, 0.79; 95% confidence interval [CI], 0.75-0.82). The final diagnoses were gutter impingement (n = 12), periprosthetic (stress) fracture (n = 5), loosening (n = 5), tarsal arthritis (n = 1), and erysipelas (n = 1). Overall, the diagnostic test characteristics of bone SPECT/CT were as follows: sensitivity of 100% (95% CI, 82%-100%), specificity of 80% (95% CI, 28%-99%), and accuracy of 96% (95% CI, 79%-100%). Gutter impingement, periprosthetic fracture, and loosening were correctly identified in all cases revealing distinct uptake patterns. Importantly, persistent diffuse uptake was frequently observed, warranting cautious interpretation. Bone SPECT/CT impacted clinical management in 86%, with symptomatic improvement in 83% of patients. CONCLUSIONS: Integrated bone SPECT/CT of painful TARs may benefit from standardized localization to reveal distinct uptake patterns representing common complications after TAR. Initial results show highly promising diagnostic value with potentially important impact on clinical management.

Clinical and Radiological Outcomes of Hallux Rigidus Treated With Cheilectomy and a Moberg-Akin Osteotomy.

BACKGROUND: This study aimed to evaluate the clinical and radiological outcome after cheilectomy and proximal phalangeal biplanar osteotomy for patients with mild and advanced stages of hallux rigidus. METHODS: A total of 105 feet (grades 0-4) were treated with cheilectomy and a Moberg-Akin osteotomy of the proximal phalanx. All patients were clinically assessed preoperatively and followed up for 12 months by range of motion, visual analog scale (VAS) pain score, American Orthopaedic Foot & Ankle Society (AOFAS) score, Short Form 36 (SF-36) score, and weightbearing radiographs. RESULTS: This operative procedure resulted in a statistically significant positive effect on mobility of the first metatarsophalangeal joint (P = .001), VAS pain score (P < .001), AOFAS score (P < .001), and SF-36 score (P < .001). CONCLUSION: Cheilectomy and biplanar osteotomy of the proximal phalanx was an effective procedure for hallux rigidus with a positive effect on clinical and radiological outcome. LEVEL OF EVIDENCE: IV, case series.

Lower Extremity Near-infrared Spectroscopy After Popliteal Block For Orthopaedic Foot Surgery.

BACKGROUND: Noninvasive measurement of cutaneous tissue oxygenation using near-infrared spectroscopy (NIRS) has become common in peri-operative care. Following institution of peripheral nerve blocks, neurovascular alterations in the blocked region have been described. OBJECTIVE: The primary aim of this study encompassed the assessment of the influence of a popliteal block on changes in regional oxygen saturation (SrO2), and the location of most prominent changes. METHOD: We conducted a prospective randomised controlled trial. Hundred twenty patients who received a popliteal block for foot surgery were included. Popliteal block was performed under echographic guidance. The patients were randomized in 3 groups according to the location of the SrO2 electrodes on the legs. Bilateral SrO2 measurements were performed simultaneously. SrO2 in the operated leg and in the control leg was measured at baseline and 1, 5, 10, 15, and 30 minutes after the perineural injection. We quantified the evolution in SrO2 by calculating over time the differences in SrO2 values between the operated and control leg (=ΔSrO2). RESULTS: At 30 minutes, ΔSrO2 increased significantly (p<0.05) at the plantar side of the foot (11.3% ± 2.9%), above the ankle (4.9% ± 1.3%) and the popliteal fossa (3.6% ± 1.2%). CONCLUSION: At 30 minutes after institution of the popliteal block, ΔSrO2 was most prominent at the plantar side of the foot as compared with measurement performed above the ankle or under the knee.

Intratest reliability in determining the subtalar joint axis using the palpation technique described by K. Kirby.

BACKGROUND: Exact determination and classification of the spatial position of the subtalar joint axis could be a predictive clinical variable in biomechanical analysis and a valuable tool in the design of functional foot orthoses. METHODS: Three clinicians with different levels of experience determined and classified the subtalar joint axis location, three times, on 52 individuals, using the clinical palpation, allocation and interpretation technique, as described by K. Kirby. RESULTS: High intratester precision (ICC 0.72 to 0.93) was found for determining the axis location (SEM, 3.72° for angle/0.27 cm for X-axis); however, classification of the spatial position of the axis has large intertester variation (κ = 0.243 to 0.494) CONCLUSIONS: The clinical palpation technique itself is reliable; the consistent attribution of a classification, in other words, interpretation, is weak.