Arthroscopically Assisted Treatment of Isolated Comminuted Trapezium Fracture: A Report of Two Cases.

CASES: Two competitive athletes with isolated comminuted trapezium fractures, sustained during American football and rugby, presented with pain and swelling of the first metacarpal base. Computed tomography confirmed isolated comminuted trapezium fractures. Arthroscopic reduction of displacement with screw fixation below the articular surface was performed through a small incision. Both patients returned to their preinjury sports levels within 2 months postoperatively. CONCLUSION: Arthroscopic treatment of isolated comminuted trapezium fractures achieved accurate reduction of articular surface displacement and preserved trapeziometacarpal joint stability with minimal soft-tissue invasion. This facilitated an early return to contact sports for the affected athletes.

Atypical Fracture of Radial Diaphysis After Sauvé-Kapandji Procedure: A Retrospective Radiographic Evaluation of Fracture Progression.

The Sauvé-Kapandji procedure (SK), which combines distal radioulnar joint arthrodesis with creation of an ulnar pseudarthrosis, achieves good outcomes with few complications for patients with distal radioulnar joint instability or arthritis. The authors describe a case of atypical fracture of the radial diaphysis that occurred in a 79-year-old woman with rheumatoid arthritis who had undergone SK 18 years earlier. The patient had taken alendronate for osteoporosis for 13 years but had discontinued treatment 2 years before onset of symptoms. Retrospective review of serial radiographs revealed focal cortical thickening at the fracture site beginning 18 months before the onset of prodromal pain and becoming more evident over time. The patient underwent surgical repair of the fracture, which had occurred at the attachment of the pronator teres. Histopathological examination of bone excised from the fracture site and from the iliac graft used for fracture repair revealed markedly fewer trabecular osteoblasts than normal and no osteoclasts, indicating severe suppression of bone turnover. It is important to evaluate the radial diaphysis on radiographs taken after SK for early signs of atypical fracture, especially in patients with rheumatoid arthritis and a history of bisphosphonate use. Given the patient's history of bisphosphonate use and the similar radiographic appearance to atypical femoral fractures, the authors applied the term atypical radial fracture to this case. [Orthopedics. 2023;46(5):e317-e320.].

Sonographic evaluation of the abductor pollicis brevis muscle reflects muscle strength recovery after carpal tunnel release.

PURPOSE: This study aimed to examine the associations between sonographic measurements of the abductor pollicis brevis (APB), grip and pinch strength, and distal motor latency (DML) in patients with carpal tunnel syndrome (CTS) before and after surgery. METHODS: We prospectively studied patients (46 hands) who underwent 1 year of postoperative follow-up after endoscopic carpal tunnel release. The patients underwent ultrasound (US) scans, grip and pinch strength assessment, a nerve conduction study, and patient-reported outcome measures (Carpal Tunnel Syndrome Instrument and Michigan Hand Outcomes Questionnaire) before and 1 year after surgery. The standardized response mean was calculated to compare the sensitivity of clinical changes in these measurements. RESULTS: US measurements (thickness of the APB and the cross-sectional area of the APB) and muscle strength (grip strength, key pinch, and tip pinch) were greater, and DML was reduced after surgery compared with those before surgery (all P < 0.05). Patient-reported outcome measures also showed clinical improvement 1 year after surgery (P < 0.05). US measurements of the APB were significantly correlated with grip and pinch strength (all P < 0.05), but not with DML, before surgery and 1 year after surgery. The standardized response mean showed a large responsiveness for US measurements of the APB and patient-reported outcome measures. CONCLUSION: US evaluation of the APB after CTS can complement the evaluation of grip and pinch strength in the clinical setting. Postoperative recovery of the APB leads to improved motor dysfunction in CTS. Therefore, US measurement of the APB could be a useful tool for evaluating motor function.

Effect of Downsized Screw Selection on Bone Healing and Postoperative Complications in Volar Plating of Distal Radius Fractures.

When performing volar plating of distal radius fractures, selecting downsized subchondral screws may prevent dorsal screw penetration (DSP), which is a risk factor for extensor tendon rupture. However, downsizing may cause loss of reduction or poor bone healing. This prospective study investigated the effect of downsized screw selection on bone healing and postoperative complications. A total of 115 patients with postoperative follow-up longer than 6 months comprised the study population. Using a depth gauge, screws that were 2-mm shorter than the measured value were selected. The DSP then was checked using dorsal tangential view (DTV) radiographs during surgery and at final follow-up. Baseline data included bone healing, loss of reduction of radiological parameters, DSP location, and postoperative complications. To assess DSP on DTV radiographs, the dorsal surface of the radius was divided into the radial and ulnar sides at the Lister tubercle, and each was further divided into 2 equal regions. These 4 regions were defined as zones 1 to 4 from the radial side. A total of 114 patients (99%) showed bone healing. Mean loss of reduction was approximately 1° and within 1 mm in radiological parameters. Eleven patients (9.6%) showed DSP during surgery or at final follow-up despite using 2-mm downsized screws. The most common site of DSP was zone 3. Extensor pollicis longus rupture occurred in 2 patients (1.7%) despite no DSP. Downsized screw selection provided a high rate of bone healing with minimum loss of reduction and a low complication rate. The extensor tendon can be torn regardless of DSP. [Orthopedics. 2021;44(2):e259-e265.].

Impairment and restoration of the blood-nerve barrier and its correlation with pain following gradual nerve elongation of the rat sciatic nerve.

Purpose: This study aimed to evaluate the time course of impairment and restoration of the blood-nerve barrier (BNB) following gradual elongation of the sciatic nerve and to clarify its association with nociception.Materials and Methods: The right femur was lengthened at a rate of 1.5 mm/day for 10 days. Von Frey tests were performed until 50 days after lengthening. Compound muscle action potentials (CMAPs) were measured to assess gross dysfunction of the elongated nerve. Evans blue-albumin tracing and immunohistochemistry for endothelial barrier antigen (EBA), rat endothelial cell antigen-1 (RECA-1), and CD68 for qualitative and quantitative analysis of the BNB and macrophage infiltration were performed for up to 50 days after cessation of lengthening in three segments of the sciatic nerves.Results: Paw-withdrawal threshold was significantly decreased at 7 days from initiation and began to recover from day 25 after lengthening. CMAPs showed delayed latency and attenuated amplitude but recovered at day 30 after cessation. On days 10 and 30 after cessation, spotted leakage of Evans blue-albumin in the endoneurium was observed, and the ratio of EBA/RECA-1-positive microvessels was significantly decreased, which subsequently recovered simultaneously in all segments on day 50 after cessation. Macrophages did not infiltrate the BNB at any time point.Conclusion: The restoration of BNB function following gradual nerve elongation was associated with the resolution of mechanical allodynia. Our findings provide insight into the association between nerve stretch injury and chronic nociception in adult male rats, which are potentially relevant to human orthopedic procedures and chronic neuropathic pain.

Idiopathic anterior dislocation of the radial head: symptoms, radiographic findings, and management of 8 patients.

BACKGROUND: Radial head dislocation may occur during trauma or in association with congenital diseases, or it may be developmental or idiopathic. Reports of idiopathic dislocation of the radial head have been scarce. The symptoms, radiographic findings, and management of idiopathic dislocation of the radial head have not been well described in the literature. METHODS: During the past 28 years, we have encountered 8 cases of idiopathic anterior dislocation of the radial head (mean patient age, 12.5 years). In only 1 case did the patient and/or the patient's parents recall any preceding trauma or injury to the affected limb. Patients' complaints included a bulging mass, pain, and limited elbow flexion. Radiographically, the shape of the radial head was flat or slightly convex. Seven of the patients were treated with open reduction of the radial head and angulation osteotomy of the ulna. The other patient's radial head was stabilized without osteotomy. RESULTS: The mean postoperative follow-up period was 4.5 years. In patients whose elbow flexion was limited before surgery, improvement to more than 125° occurred. The bulging mass in the cubital fossa disappeared. None of the patients complained of disability during activities of daily living or sports participation. Radiographically, the radial head remained in the reduced position in all patients in whom open reduction of the radial head with angulation osteotomy of the ulna was performed. CONCLUSIONS: We have described the symptoms, radiographic characteristics, and treatment of idiopathic anterior dislocation of the radial head. Open reduction of the radial head combined with angulation osteotomy of the ulna yielded favorable results both clinically and radiographically.

Sonographic morphometry of abductor pollicis brevis: can direct contact yield images comparable with those obtained by the water bath technique?

PURPOSE: This study sought to compare ultrasound-guided measurements of the abductor pollicis brevis (APB) using the water bath technique (WBT) and the direct contact method (DM) and investigate whether the DM can reproduce the measurements that would be obtained with a non-contact method, such as the WBT. METHODS: The APB muscles of 80 hands (40 healthy adults) were measured. The WBT was performed in a plastic container filled with water. The probe was placed adjacent to the skin surface without contact. In the DM, sonographic images were obtained with the probe and skin separated by sufficient transmission gel. The muscle thickness and cross-sectional area (CSA) were calculated with both methods. All subjects were examined three times by two examiners to estimate the inter- and intra-observer reliability. Bland-Altman analysis was performed to examine the agreement between the methods. RESULTS: No significant differences in the thickness or CSA of the APB were found. The interclass correlation coefficients for the WBT and DM showed almost perfect intra- and inter-observer reliability (range 0.87-0.94). There was no systematic bias between the techniques in the Bland-Altman analysis. CONCLUSION: Similar to the WBT, the DM provides measurements of the APB thickness and CSA without causing morphometric changes.

Sonographic monitoring of endoscopic carpal tunnel release.

We evaluated the effectiveness of sonographic monitoring of endoscopic carpal tunnel release for the prevention of median nerve or arterial injury and incomplete release of the flexor retinaculum (FR). When the outer tube (OT) was inserted, we used sonography to confirm the relationship of the OT, median nerve, ulnar artery, and superficial palmar arch. Under real-time US monitoring, the OT was lifted up before and after FR release, the so-called lift-up test, to evaluate its mobility under sonography and confirm complete FR release. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:597-599, 2016.

Role of sodium channels in recovery of sciatic nerve-stretch injury in rats.

INTRODUCTION: To elucidate the mechanism of functional recovery after gradual nerve-stretch injury, we used rats in which the femur length was increased by 15 mm at 1.5 mm/day. METHODS: We performed electrophysiology, mRNA analysis of tetrodotoxin-resistant voltage-gated sodium channels (TTX-R VGSCs) in dorsal root ganglia, and histology of unmyelinated sciatic nerve fibers and examined pain thresholds at 1, 10, 20, and 30 days after cessation of lengthening. RESULTS: Electrophysiology revealed conduction block after cessation that recovered after 30 days. TTX-R VGSC levels decreased immediately after cessation but were restored after 10 (Nav1.9) or 20 (Nav1.8) days. Histology revealed that injured unmyelinated nerve fibers regenerate 30 days after cessation. Pain threshold decreased gradually during lengthening but had not recovered to the control group level after 30 days. CONCLUSIONS: Early restoration of TTX-R VGSC mRNA in dorsal root ganglia preceded functional recovery of stretched nerves before regeneration of injured unmyelinated nerve fibers.

Altered expression of sodium channel distribution in the dorsal root ganglion after gradual elongation of rat sciatic nerves.

To elucidate the pathophysiological mechanisms underlying chronic nerve-stretch injury, we gradually lengthened rat femurs by 15 mm at the rate of 0.5 mm/day (group L, n = 13). The control groups comprised sham-operated (group S, n = 10) and naive (group N, n = 8) rats. Immediately after the lengthening, we performed a conduction study on their sciatic nerves and harvested samples. Electrophysiological and histological analyses showed mild conduction slowing and axonal degeneration of unmyelinated fibers in group L rats. Altered mRNA expression of the voltage-gated sodium channels in the dorsal root ganglion was also observed. Tetrodotoxin-resistant (TTX-R) sodium-channel Nav1.8 mRNA expression was significantly decreased and TTX-R sodium-channel Nav1.9 mRNA expression showed a tendency to decrease when compared with the mRNA expressions in the control groups. However, tetrodotoxin-sensitive (TTX-S) sodium-channel Nav1.3 mRNA expression remained unaltered. The immunohistochemical alteration of Nav1.8 protein expression was parallel to the results of the mRNA expression. Previous studies involving neuropathic states have suggested that pain/paresthesia is modulated by a subset of sodium channels, including downregulation and/or upregulation of TTX-R and TTX-S sodium channels, respectively. Our findings indicate that Nav1.8 downregulation may be one of the pathophysiological mechanisms involved in limb lengthening-induced neuropathy.