Dorsal Approach for Management of Proximal Interphalangeal Joint Flexion Contracture.

Proximal interphalangeal (PIP) joint contracture is a common, difficult clinical problem that can arise from minor trauma. Management is difficult because outcomes are unpredictable and often poor, due to residual flexion deformities postoperatively. The dorsal approach for flexion contracture of the PIP joint is not discussed in present literature. In this technique guide, we wish to describe and explain the rationale for a dorsal approach. In our experience, a dorsal approach allows for ease of access to all pathologic structures, with simple positioning of the digit to allow access to volar structures, as well as when addressing more than one digits with a PIP contracture. Finally, similar to the midaxial approach, the dorsal approach also eliminates any volar soft tissue concerns and need for supplemental coverage.

Does Patient Sex Affect Ultrasound Cutoff Values for Severity Grading of Carpal Tunnel Syndrome?

PURPOSE: A growing body of evidence supports ultrasound (US) as an alternative first-line confirmatory test for carpal tunnel syndrome (CTS). Recent studies have demonstrated a correlation of US cross-sectional area with electrodiagnostic (EDX)-determined severity; however, it is unclear whether patient sex affects the cutoff values used for determining severity. The purpose of this study was to determine if patient sex affects US graded severity when using EDX as the reference standard. METHODS: A cohort of 367 women and 46 men, aged 18-90 years, from 1 orthopedic hand surgeon's practice underwent EDX and US. Distal motor latency and distal sensory latency of the median nerve were recorded. Severity was classified using a modified Bland severity scale. The US measurements of the cross-sectional area of the median nerve at the wrist crease were acquired by a fellowship-trained hand surgeon. Separate receiver operator characteristic curve analyses of the male and female groups were performed for US cutoff values. RESULTS: The cutoff value in both the female (F) and male (M) patients was 11 mm2 for mild (area under the curve = 0.76 F; 0.78 M), 12 mm2 for moderate (area under the curve = 0.75 F; 0.73 M), and 13 mm2 for severe (area under the curve = 0.75 F; 0.71 M) CTS. The sensitivity of the cutoffs for mild, moderate, and severe CTS in the female and male groups was 49% and 56%, 44% and 50%, and 49% and 44%, respectively. The specificity of the cutoffs for mild, moderate, and severe CTS in the female and male groups was 75% and 79%, 74% and 82%, and 83% and 78%, respectively. CONCLUSIONS: Patient sex does not appear to have a significant impact on the determination of CTS severity graded using US cutoff values. Ultrasound can be used to grade the severity of CTS with a 75% to 85% specificity but low sensitivity. A cutoff value of 13 mm2 can be used to classify CTS as severe. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

A Comparison of Changes in Median Nerve Cross-sectional Area Between Endoscopic and Mini-Open Carpal Tunnel Release.

Purpose: The purpose of this study was to determine whether there is a difference in the change in cross-sectional area (CSA) of the median nerve in patients undergoing carpal tunnel release (CTR) based on surgical technique and whether this change is associated with changes in patient-reported outcomes evaluated using the Carpal Tunnel Syndrome Assessment Questionnaire. Methods: Individuals with carpal tunnel syndrome were evaluated with ultrasound and the CTSAQ before and 6 weeks after surgery. Patients were eligible for inclusion if they underwent either a mini-open CTR (MOCTR) or endoscopic CTR (ECTR). A single surgeon performed all surgeries. Changes in median nerve CSA, Carpal Tunnel Syndrome Assessment Questionnaire scores, and their associated surgical technique (MOCTR vs ECTR) were analyzed. Results: A total of 77 patients were enrolled, 13 of whom were lost to follow-up, which left 64 for analysis. Of those, 42 patients underwent ECTR and 22 MOCTR. Mean age was 55 years; there were 52 women and 12 men. Mean changes in CSA for endoscopic and mini-open techniques from before to 6 weeks after surgery were -1.9 mm2 (95% confidence interval [CI], -1.1 to -2.7) and +0.6 mm2 (95% CI, -1.6 to 0.4), respectively. Mean Symptom Severity Scores improved after endoscopic and mini-open release by 1.7 (95% CI, 1.4-2.1) and 1.5 (95% CI, 1.2-1.9), respectively. Mean Functional Status Scores improved after endoscopic and mini-open release by 1.2 (95% CI, 0.9-1.9) and 0.7 (95% CI, 0.03-1.3), respectively. Conclusions: Patients undergoing ECTR demonstrated decreased median nerve CSA, whereas those undergoing MOCTR demonstrated increased median nerve CSA at 6 weeks. All patients undergoing surgical intervention demonstrated improvement in both Symptom Severity Scores and Functional Status Scores after surgery. Whereas both techniques successfully improve patient outcome scores, an increase in CSA after MOCTR may be seen in the initial postoperative period, potentially contributing to a slower short-term improvement in outcome in functional scores compared with ECTR. Type of study/level of evidence: Therapeutic IV.

Changes in Nerve Conduction Studies After Distal Radius Fracture Fixation Using a Volar Approach and Locked Plate.

Purpose: To determine whether there are changes in nerve conduction studies (NCS) of the median nerve after distal radius fracture (DRF) and to determine how operative fixation through a volar approach with a locking plate contributes to nerve conduction changes. We hypothesized that a considerable percentage of patients would have electrodiagnostic evidence of median neuropathy at the wrist after fracture, but fixation with a volar locked plate would not worsen the electrodiagnostic findings. Methods: This was a prospective cohort study of 14 neurologically asymptomatic patients who underwent surgical treatment of an isolated DRF using a volar plate. All patients underwent surgery within 2 weeks of injury. On the day of surgery and at the 6-week follow-up, patients were clinically examined, Quick-Disabilities of the Arm, Shoulder, and Hand questionnaire was completed, and patients underwent NCS using a handheld device with the unaffected limb, which was used as a comparison. Preoperative and postoperative nerve function were compared with the unaffected limb as a baseline. Results: Patients without symptoms after DRF had a 28% incidence of prolonged latencies compared with reference values for the device used. Distal sensory latencies of the median nerve were 3.64 ± 0.32 ms in the unaffected arm, 3.76 ± 0.70 ms before surgery, and 3.81 ± 0.52 ms after surgery. Distal motor latencies of the median nerve were 3.91 ± 0.59, 3.60 ± 0.68, and 3.88 ± 0.36 ms in respective arms and time points. Quick-Disabilities of the Arm, Shoulder, and Hand scores improved from 77 before surgery to 46 at 6 weeks. Conclusions: Asymptomatic patients may satisfy nerve conduction criteria for median neuropathy at the wrist after DRF; however, open reduction and treatment with a volar locked plate has no significant effect on NCS findings. Type of study/level of evidence: Prognostic II.

A Prospective Comparison of Diagnostic Tools for the Diagnosis of Carpal Tunnel Syndrome.

PURPOSE: Nerve conduction studies (NCS), CTS-6, Wainner, Kamath, and Lo are diagnostic tests that are used to diagnose carpal tunnel syndrome (CTS). To our knowledge, no study has compared the sensitivity and specificity of these 5 tests with one another. The purpose of this study is to compare NCS, CTS-6, Wainner, Kamath, and Lo using clinical diagnosis by a hand fellowship-trained orthopedic surgeon as reference standard. METHODS: A hand fellowship-trained surgeon completed the CTS-6, Wainner, Kamath, and Lo diagnostic tools. Cutoff values for a positive test were based on values in the literature, if available. The NCS were performed by a certified electrodiagnostic physician according the standards of the American Association of Neuromuscular and Electrodiagnostic Medicine and were interpreted using absolute latencies, relative latencies, and combined sensory index. Sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were calculated for the tests using clinical diagnosis as the reference standard. RESULTS: A total of 408 wrists from 250 patients were analyzed in the study. The NCS had the highest sensitivity (94%) but also the lowest specificity (50%) of any of the diagnostic tests. Using a cutoff of 18, CTS-6 had the highest specificity (99%). The NCS had the highest area under the curve at 74%, followed closely by the Kamath at 69%. CONCLUSIONS: The NCS were traditionally felt to be a strong confirmatory test given their high specificity. However, this prospective series demonstrated that NCS had the lowest specificity of any diagnostic test. CLINICAL RELEVANCE: Consideration should be given to using alternative diagnostic tests/tools based on the results of this study.

A Comparison of Plain Radiographs and Computed Tomography for Determining Canal Diameter of the Distal Phalanx.

PURPOSE: To compare plain radiographs and computed tomography (CT) when determining the narrowest diameter of the medullary canal of the distal phalanx. METHODS: A database review identified 48 patients (23 male, 25 female) who underwent a CT scan of the hand and plain radiographs of the same hand. Using digital imaging software, the smallest diameter of the medullary canal was measured for each finger (index, middle, ring, little) on CT and on radiographs. RESULTS: The narrowest diameter of the medullary canal was measured on the axial CT and lateral hand radiograph at the transition between the tuft and the distal phalanx shaft. The mean narrowest diameters on plain radiographs for the index, middle, ring, and little fingers were 1.4 mm, 1.4 mm, 1.4 mm, and 1.1 mm, respectively. The mean diameters on CT were 1.2 mm, 1.3 mm, 1.2 mm, and 1.0 mm, respectively. Men had larger medullary canal dimensions (1.5-1.7 mm) than women (0.8-1.2 mm). CONCLUSIONS: The differences in canal diameter measurements between plain radiograph and CT were small and likely clinically insignificant. CLINICAL RELEVANCE: Lateral radiographs can be used for preoperative planning when estimating the size of the distal phalanx intramedullary canal.

Anatomy of the flexor digitorum profundus insertion.

PURPOSE: To describe the anatomical insertion of the flexor digitorum profundus (FDP) on the distal phalanx. METHODS: The FDP insertion to the index, middle, ring, and little fingers were dissected in 10 fresh-frozen cadavers. The FDP tendon was dissected off the volar plate, which was elevated from proximal to distal, before the distal phalanx was disarticulated. The distal phalanx was then inked and the FDP was sharply dissected from bone. The insertion length, width, and distance of the insertion from the joint were measured and the insertion surface area and centroid of the FDP insertion were calculated. RESULTS: The average insertion length and width were 6.2 mm (range, 5.1-7.0 mm) and 7.9 mm (range, 6.9-8.4 mm), respectively. The average surface area of the distal phalanx occupied by the FDP tendon, for all fingers, was 20% (range, 15%-27%). The average distance from the most proximal insertion to the joint surface was 1.2 mm (range, 0.4-2.1 mm) and the calculated centroid of the FDP insertion from the distal interphalangeal joint was 3.6 mm (range, 2.5-5.1 mm) or approximately 20% of the distal phalangeal length. CONCLUSIONS: These findings may aid anatomical attachment of the FDP tendon in the treatment of zone I injuries. CLINICAL RELEVANCE: A better understanding of the anatomy of the FDP insertion may aid proper repair positioning in the treatment of zone I injuries.