Rasch analysis of the carpal tunnel syndrome instrument.

BACKGROUND: The carpal tunnel syndrome instrument (CTSI) is the most widely used patient-reported outcome measure (PROM) in carpal tunnel syndrome (CTS). However, CTSI is an ordinal-type questionnaire and might have caused misinterpretations of the PROM between surgical outcomes of CTS (Camitz and extra/open carpal tunnel release). PURPOSE: This study aims to convert the CTSI to an interval scale using Rasch analysis (RA) and evaluate the outcome differences between the original and transformed scales. STUDY DESIGN: Prospective control study. METHODS: Four hundred twenty-four patients with 567 CTSs had been interviewed for CTSI perioperatively and treated with either endoscopic/open carpal tunnel release or Camitz tendon transfer. Each CTSI was analyzed for dimensionality, fit statistics, and a transformation of the ordinal-to-interval scale by RA. We compared the two groups perioperative scores of three CTSI versions (original 11-item, modified 8-item, and transformed 8-item). RESULTS: Based on the RA, the original CTSI was not unidimensional. We identified two dimensions. After removing misfit items, the perioperative course of each score by three versions of each dimension was compared (Repeated 2-factor analysis of variance). The transformed interval scales of CTSI provided different assessments of score changes from the ordinal scale of CTSI analyses. CONCLUSIONS: Original CTSI consisted of ordinal scale items that yielded different conclusions than scores converted to interval scale by Rasch analysis. CTSI should convert into an interval scale after reclassifying dimensionality by Latent Factor Analysis and removing misfit items.

Arthroscopic Removal of a Missed Wooden Foreign Body in the Metacarpophalangeal Joint.

We report a case of a missed wooden foreign body in the metacarpophalangeal (MP) joint of the right little finger following a workplace injury. The patient presented to our institution with a persisted pain and limited range of motion of the MP joint 1 week following the injury. Plain radiographs detected no foreign body or fractures. However, detailed examination as ultrasonography (USG) and computed tomography revealed the presence of a foreign body of 10 × 1.5 mm size in the MP joint capsule. The excision of the radiolucent foreign body was performed arthroscopically and was confirmed successful removal using intraoperative USG. The foreign body was recognized as a wooden piece. The patient was immediately pain free postoperatively and regained full range of motion. Arthroscopy can be a practical, reliable method to remove a radiolucent foreign body located in a small joint in a minimally invasive manner, and USG can help surgeons confirm no remnants left.

Re-evaluation of the Indications for the Camitz Procedure in Severe Carpal Tunnel Syndrome.

PURPOSE: The modified Camitz procedure has been used to improve thumb opposition in patients with severe carpal tunnel syndrome (CTS), although its indications remain controversial. This study compared the functional recovery of thumb opposition following carpal tunnel release with and without a concomitant Camitz procedure. We used the Carpal Tunnel Syndrome Instrument questionnaire (CTSI) and the compound muscle action potential of the abductor pollicis brevis (APB-CMAP) to assess the recovery. METHODS: Five hundred sixty-seven hands underwent surgical treatment for CTS following electrophysiologic studies and the CTSI. The procedures included carpal tunnel release (either endoscopic carpal tunnel release [ECTR] or open carpal tunnel release [OCTR]) and OCTR with a Camitz procedure. One hundred thirty-six patients with absent preoperative APB-CMAP constituted the material of our study. The CTSI and APB-CMAP recoveries between the "ECTR/OCTR group" and the "Camitz group" were compared before surgery and at three, six, and 12 months after surgery. RESULTS: There were no statistically significant differences in recovery between the "ECTR/OCTR group" and the "Camitz group" according to the three scales of CTSI (symptom severity scale, functional state scale, and FS-2 item, buttoning clothes: an alternative test of thumb opposition) and the APB-CMAP. CONCLUSION: Carpal tunnel release procedures resulted in the useful recovery of thumb opposition without the need for Camitz, even if APB-CMAP did not fully recover. The action of the other synergistic muscles acting on the thumb and the sensory recovery may have contributed to the recovery of thumb opposition. The Camitz procedure also may be only rarely indicated for hands affected by severe CTS. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Diagnostic Accuracy of Magnetic Resonance Imaging With 3-Dimensional T2-SPACE Techniques for Preganglionic Injury of the Brachial Plexus.

PURPOSE: An accurate diagnosis of the site and severity of a brachial plexus injury is imperative for selecting the appropriate management. Conventional magnetic resonance imaging (MRI) does not allow for the precise interpretation of preganglionic injuries (pre-GIs), especially intravertebral canal injuries. We developed 4 MRI sequences of conventional 1.5-tesla 3-dimensional T2-weighted turbo spin echo sampling perfection with the application of optimized contrasts using different flip angles evolution (T2-SPACE) images to clearly visualize each component of the brachial plexus. The purpose of this study was to introduce basic normal and pathologic findings of our current MRI approach, focusing on its diagnostic accuracy for pre-GIs. METHODS: We initially examined 119 patients with brachial plexus injuries who underwent surgical exploration by MRI using 4 sequences of the 1.5-tesla 3-dimensional T2-SPACE technique. We obtained coronal, transverse, coronal oblique, and coronal cuts of T2 short time inversion recovery. The images of 595 roots were interpreted by multiple-image synchronizing techniques of the 4 views to precisely interpret the presence of spinal cord edema, numbers of anterior and posterior rootlets, sites of ganglions, meningeal cysts, and the "black line sign" (displaced ruptured dura or bundles of ruptured rootlets). We assessed the accuracy, sensitivity, and specificity of these abnormal findings with regard to diagnosing pre-GIs by comparing surgical exploration. RESULTS: The absence or decreased numbers of anterior and posterior rootlets and displacement of ganglions were definitive evidence of pre-GIs and the other findings, like spinal cord edema, meningeal cysts, and black line signs, were predictive signs. CONCLUSIONS: The synchronizing techniques of the four 1.5-tesla 3-dimensional T2-SPACE images provided high diagnostic accuracy of pre-GIs. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.

Comminuted Dorsal Ulnar Fragment in Distal Radius Fractures Treated Using the Integrated Compression Screw With a Mini-Plate.

Stabilization for displaced dorsoulnar fragments in distal radius fractures is challenging to treat with conventional volar locking plates alone. The integrated compression screw combined with a volar locking plate has been introduced as an additional tool to stabilize the dorsoulnar fragment and has been reported to work effectively. However, the compression screw is unable to stabilize a comminuted dorsal ulnar fragment; therefore, it is necessary to consider using an additional dorsal plate. We have developed a modified surgical technique to stabilize a comminuted dorsal intra-articular fragment by combining the integrated compression screw with a mini-plate as a washer or a buttress.