A cadaveric study of ulnar nerve strain at the elbow associated with cubitus valgus/varus deformity.

BACKGROUND: Cubital tunnel syndrome can be caused by overtraction and dynamic compression in elbow deformities. The extent to which elbow deformities contribute to ulnar nerve strain is unknown. Here, we investigated ulnar nerve strain caused by cubitus valgus/varus deformity using fresh-frozen cadavers. METHODS: We used six fresh-frozen cadaver upper extremities. A strain gauge was placed on the ulnar nerve 2 cm proximal to the medial epicondyle of the humerus. For the elbow deformity model, osteotomy was performed at the distal humerus, and plate fixation was performed to create cubitus valgus/varus deformities (10°, 20°, and 30°). Ulnar nerve strain caused by elbow flexion (0-125°) was measured in both the normal and deformity models. The strains at different elbow flexion angles within each model were compared, and the strains at elbow extension and at maximum elbow flexion were compared between the normal model and each elbow deformity model. However, in the cubitus varus model, the ulnar nerve deflected more than the measurable range of the strain gauge; elbow flexion of 60° or more were considered effective values. Statistical analysis of the strain values was performed with Friedman test, followed by the Williams' test (the Shirley‒Williams' test for non-parametric analysis). RESULTS: In all models, ulnar nerve strain increased significantly from elbow extension to maximal flexion (control: 13.2%; cubitus valgus 10°: 13.6%; cubitus valgus 20°: 13.5%; cubitus valgus 30°: 12.2%; cubitus varus 10°: 8.3%; cubitus varus 20°: 8.2%; cubitus varus 30°: 6.3%, P < 0.001). The control and cubitus valgus models had similar values, but the cubitus varus models revealed that this deformity caused ulnar nerve relaxation. CONCLUSIONS: Ulnar nerve strain significantly increased during elbow flexion. No significant increase in strain 2 cm proximal to the medial epicondyle was observed in the cubitus valgus model. Major changes may have been observed in the measurement behind the medial epicondyle. In the cubitus varus model, the ulnar nerve was relaxed during elbow extension, but this effect was reduced by elbow flexion.

Simultaneous Bilateral Chronic Volar Lunate Dislocation: A Case Report.

CASE: A 24-year-old professional judo competitor suffered injuries to both the wrists when he fell on his back while lifting a 90-kg barbell in the bilateral dorsiflexed wrist position. Simultaneous bilateral volar lunate dislocation had been missed for a year. The degenerated lunates were simultaneously removed using a palmar approach. At 12 months postoperatively, the patient returned to judo competitions without pain. Radiography showed no progression of the intercarpal alignment abnormality. CONCLUSION: Simultaneous bilateral chronic volar lunate dislocation is extremely rare. Long-term follow-up is necessary to check for carpal alignment.

Acromioclavicular joint instability on cross-body adduction view: the biomechanical effect of acromioclavicular and coracoclavicular ligaments sectioning.

BACKGROUND: The acromioclavicular (AC) and coracoclavicular (CC) ligaments are important stabilizers of the AC joint. We hypothesized that AC and trapezoid ligament injuries induce AC joint instability and that the clavicle can override the acromion on cross-body adduction view even in the absence of conoid ligament injury. Accordingly, we investigated how sectioning the AC and CC ligaments contribute to AC joint instability in the cross-body adduction position. METHODS: Six fresh-frozen cadaveric shoulders were used in this study, comprising five male and one female specimen, with a mean age of 68.7 (range, 51-87) years. The left side of the trunk and upper limb, and the cervical and thoracic vertebrae and sternum were firmly fixed with an external fixator. The displacement of the distal end of the clavicle relative to the acromion was measured using an electromagnetic tracking device. We simulated AC joint dislocation by the sequential resection of the AC ligament, AC joint capsule, and CC ligaments in the following order of stages. Stage 0: Intact AC and CC ligaments and acromioclavicular joint capsule; stage 1: Completely sectioned AC ligament, capsule and joint disc; stage 2: Sectioned trapezoid ligament; and stage 3: Sectioned conoid ligament. The superior clavicle displacement related to the acromion was measured in the horizontal adduction position, and clavicle overriding on the acromion was assessed radiologically at each stage. Data were analyzed using a one-way analysis of variance and post-hoc tests. RESULTS: Superior displacement was 0.3 mm at stage 1, 6.5 mm at stage 2, and 10.7 mm at stage 3. On the cross-body adduction view, there was no distal clavicle overriding at stages 0 and 1, and distal clavicle overriding was observed in five cases (5/6: 83%) at stage 2 and in six cases (6/6: 100%) at stage 3. CONCLUSION: We found that AC and trapezoid ligament sectioning induced AC joint instability and that the clavicle could override the acromion on cross-body adduction view regardless of conoid ligament sectioning. The traumatic sections of the AC and trapezoid ligament may lead to high grade AC joint instability, and the distal clavicle may subsequently override the acromion.

Impacted intraarticular fragments of distal radius fractures: A radiographic characterization and analysis of reliability and diagnostic accuracy.

BACKGROUND: Reduction using ligamentotaxis may not be effective enough to treat impacted intraarticular fragments of distal radius fractures. Articular incongruence resulting from the loss of reduction is a risk factor for postoperative osteoarthritis and worse clinical outcome. This study aimed to analyze the radiographic characterization of the impacted intraarticular fragments of distal radius fractures using two/three-dimensional computed tomography (CT). Further, we assessed the reliability and diagnostic accuracy in detecting the fragments using plain radiographs. METHODS: We analyzed 167 three-dimensional CT images of the intraarticular distal radius fractures and selected 12 fractures with impacted intraarticular fragments. We recorded the location, size, and displacement of the fragment using CT images. In addition, six examiners evaluated 25 fractures including those 12 fractures having the fragments using plain radiographs for detecting the fragments and their displacements. Further, we evaluated the reliability and diagnostic accuracy of the plain radiographs in the detection of the fragment. RESULTS: Fifteen impacted intraarticular fragments were found in 12 wrists. The displacement of the scaphoid facet fragment was significantly larger than that of the lunate facet fragment in CT measurement (7.0 mm and 3.6 mm). Inter and intraobserver reliability of the diagnosis for the fragment in plain radiographs were poor and fair (κ: 0.14 and κ:0.27). Diagnostic accuracy in detecting the fragment in plain radiographs generated mean sensitivity: 0.4, mean specificity: 0.73, and mean accuracy: 0.58. The mean sensitivity in detecting a lunate facet fragment was lower than that of a scaphoid facet fragment in plain radiographs (0.24 and 0.44). CONCLUSION: Impacted intraarticular fragments were found in 7% of intraarticular distal radius fractures. We observed low reliability and sensitivity in detecting the fragment using plain radiographs. Preoperative recognition of the fragments using plain radiograph were difficult, even though the magnitude of step-off of the scaphoid facet fragment was large.

Soft-tissue reconstruction after soft-tissue sarcoma resection: the clinical outcomes of 24 patients.

PURPOSE: Pedicle or free-flap reconstruction is important in surgical sarcoma management. Free flaps are indicated only when pedicle flaps are considered inadequate; however, they are associated with a higher risk of flap failure, longer surgical times, and technical difficulty. To determine the skin defect size that can be covered by a pedicle flap, we investigated the clinical outcomes and complications of reconstruction using pedicle flaps vs. free flaps after sarcoma resection. METHODS: We retrospectively studied the medical records of 24 patients with soft-tissue sarcomas who underwent reconstruction using a pedicle (n = 20) or free flap (n = 4) following wide tumour resection. RESULTS: All skin defects of the knee, lower leg, and ankle were reconstructed using a pedicle flap. Skin defects of the knee, lower leg, and ankle were covered by up to 525 cm2, 325 cm2, and 234 cm2, respectively. The amount of blood loss was significantly greater in the free-flap group than in the pedicle flap group (p = 0.011). Surgical time was significantly shorter in the pedicle flap group than in the free-flap group (p = 0.006). Total necrosis was observed in one (25%) patient in the free-flap group; no case of total necrosis was observed in the pedicle flap group. CONCLUSION: Less blood loss, shorter surgical time, and lower risk of total flap necrosis are notable advantages of pedicle flaps over free flaps. Most skin defects, even large ones, of the lower extremities following sarcoma resection can be covered using a single pedicle flap or multiple pedicle flaps.

Treatment of painful median nerve neuroma using pedicled vascularized lateral antebrachial cutaneous nerve with adipofascial flap: a cadaveric study and exploration of clinical application.

The most common procedure for the treatment of painful median nerve neuroma is coverage with vascularized soft tissue following external neurolysis. However, the ideal treatment should include reconnecting the proximal and distal stumps of the damaged nerve to allow the growth of regenerating axons to their proper targets for a functional recovery. We developed a useful technique employing radial artery perforator adipofascial flap including the lateral antebrachial cutaneous nerve (LABCN) to repair the median nerve by vascularized nerve grafting and to achieve coverage of the nerve with vascularized soft tissue. In an anatomical study of 10 fresh-frozen cadaver upper extremities, LABCN was constantly bifurcated into two branches at the proximal forearm (mean: 8.2 cm distal to the elbow) and two branches that run in a parallel manner toward the wrist. The mean length of the LABCN branches between the bifurcating point and the wrist was 18.2 cm, which enabled inclusion of adequate length of the LABCN branches into the radial artery perforator adipofascial flap. The diameters of the LABCN branches (mean: 1.7 mm) were considered suitable to bridge the funiculus of the median nerve defect after microsurgical internal neurolysis. In all cadaver upper extremities, the 3-cm median nerve defect at the wrist level could be repaired using the LABCN branches and covered with the radial artery perforator adipofascial flap. On the basis of this anatomical study, the median nerve neuroma was successfully treated with radial artery perforator adipofascial flap including vascularized LABCN branches.

Arthroscopic Lunate Excision Provides Excellent Outcomes for Low-Demand Patients with Advanced Kienböck's Disease.

PURPOSE: To examine the clinical outcomes of arthroscopic lunate excisions for advanced Kienböck's disease. METHODS: Fifteen patients (six men and nine women; mean age: 65 years; range: 48-83 years) with advanced Kienböck's disease, who underwent arthroscopic lunate resection between April 2008 and March 2016, were reviewed clinically and radiographically after a follow-up of >2 years (mean: 29 months; range: 24-60 months). Clinical parameters, such as wrist range of motion, grip strength, Disabilities of the Arm, Shoulder, and Hand (DASH) score, and patient-rated wrist evaluation (PRWE) score were evaluated. Radiographic parameters included radioscaphoid angle, scaphocapitate angle, carpal height ratio, ulnar-triquetrum distance, and the scaphoid-triquetrum distance. Wilcoxon's signed-rank test was used to compare measurement results. RESULTS: During the final follow-up, patients exhibited significant improvements, such as 42.9° in wrist range of motion (P = .009), 24.5% of the contralateral side in grip strength (P = .001), 26.2 points in DASH score (P = .002), and 37.8 points in PRWE score (P < .001), compared with the preoperative values. The radioscaphoid and scaphocapitate angles significantly increased by 4.8° (P = .0027) and 3.7° (P = .0012), respectively. The carpal height ratio, ulnar-triquetrum distance, and scaphoid-triquetrum distance significantly decreased by 0.05 (P < .001), 2.6 mm (P < .001), and 1.3 mm (P = .0012), respectively. CONCLUSIONS: Our results suggest that arthroscopic lunate excisions provided excellent postoperative pain relief and functional recovery within 2 years of follow-up. Changes in carpal alignment and stress concentration on the radial side of the carpal bones could occur in the long term; however, arthroscopic lunate excision can be a good surgical option for treating low-demand patients with advanced Kienböck's disease. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Partial Trapeziotrapezoid Resection and Thumb Range of Movement After Trapeziometacarpal Joint Fusion-A Biomechanical Study.

PURPOSE: Trapeziometacarpal (TMC) joint arthrodesis is an effective treatment for stage III osteoarthritis. Although this procedure alleviates thumb pain and restores grip power and pinch strength, persistent limitation of thumb movement is inevitable. This biomechanical study aimed to investigate the altered kinematics of thumb circumduction motion after TMC joint arthrodesis and subsequent excision of the trapeziotrapezoid (TT) and trapezio-second metacarpal (T-2MC) joint spaces. METHODS: Eight cadaver upper extremities were mounted on a custom testing apparatus. The hand and carpal bones were fixed to the apparatus, except for the first metacarpal bone, trapezium, and trapezoid. A 50-g load was applied at the tip of the first metacarpal head to generate passive thumb circumduction. An electromagnetic tracking system measured the angular and rotational displacement of the first metacarpal. All specimens were tested in 4 conditions: intact, after simulated TMC joint fusion, after subsequent excision of 3 mm of bone at the TT joint space, and after additional 3 mm resection at the T-2MC joint space. RESULTS: After simulated TMC arthrodesis, the range of angular motion of thumb circumduction decreased to 25% that of the intact thumb. Subsequent resections at the TT and T-2MC joint spaces increased circumduction ranges to 49% (TT joint) and 73% (TT plus T-2MC joints) that of the intact thumb. The range of thumb rotational motion showed a similar trend. CONCLUSIONS: Trapeziometacarpal arthrodesis decreased the range of both angular and rotational motion during thumb circumduction. Subsequent resections at the paratrapezial space increased the range of thumb motion, suggesting that hypermobility of the paratrapezial joints increases thumb mobility after TMC joint fusion. CLINICAL RELEVANCE: Patients with hypermobile paratrapezial joints may have larger thumb movement after TMC joint fusion. Additional resections of the TT and T-2MC joint spaces may further mobilize the thumb in patients who complain of stiffness after TMC fusion.

Biomechanical comparison of arthroscopic and open lunate excisions in the cadaveric wrist.

BACKGROUND: In advanced Kienböck disease, unreconstructible lunate should be excised as a salvage procedure. There is a lack of information about the biomechanical approaches evaluating the carpal kinematics after lunate excision. We hypothesized that arthroscopic lunate excision would not break the ring structure of the proximal carpal row, preventing carpal instability. We aimed to investigate changes in carpal kinematics following arthroscopic and open lunate excisions. METHODS: We used upper extremities from five fresh cadavers and simulated arthroscopic and open lunate excisions. Arthroscopic lunate excision was performed to preserve the attachment sites of intrinsic and extrinsic carpal ligaments to the lunate. Open lunate excision was conducted with sectioning of the intrinsic and extrinsic carpal ligaments. Using a three-dimensional space electromagnetic tracking device, rotation angles of the scaphoid and triquetrum and the change of scaphotriquetrum distance were measured under axial loading. We compared the rotation angles and the change of scaphotriquetrum distance among intact wrists, open, and arthroscopic lunate excisions. FINDINGS: No Significant differences in the rotation angle of the scaphoid and triquetrum or the change of scaphotriquetrum distance were found between intact wrist and arthroscopic lunate excision. The triquetrum significantly dorsiflexed and supinated in wrists with open lunate excisions compared with intact wrists. Significant differences in the change of scaphotriquetrum distance were found between intact and openly excised wrists and between arthroscopic and open excisions. INTERPRETATION: Arthroscopic lunate excision potentially prevented kinematic change of the proximal carpal row under axial loading by maintaining the integrity of attachment sites of carpal ligaments.

The Role of the Acromioclavicular Ligament in Acromioclavicular Joint Stability: A Cadaveric Biomechanical Study.

BACKGROUND: Acromioclavicular (AC) joint dislocation is evaluated using the radiologically based Rockwood classification. The relationship between ligamentous injury and radiological assessment is still controversial. PURPOSE/HYPOTHESIS: To investigate how the AC ligament and trapezoid ligament biomechanically contribute to the stability of the AC joint using cadaveric specimens. The hypothesis was that isolated sectioning of the AC ligament would result in increased instability in the superior direction and that displacement >50% of the AC joint would occur. STUDY DESIGN: Controlled laboratory study. METHODS: Six shoulders from 6 fresh-frozen cadavers were used in this study. Both the scapula and sternum were solidly fixed on a customized wooden jig with an external fixator. We simulated distal clavicular dislocation with sequential sectioning of the AC and coracoclavicular (CC) ligaments. Sectioning stages were defined as follows: stage 0, the AC ligament, CC ligament, and AC joint capsule were left intact; stage 1, the anteroinferior bundle of the AC ligament, joint capsule, and disk were sectioned; stage 2, the superoposterior bundle of the AC ligament was sectioned; and stage 3, the trapezoid ligament was sectioned. The distal clavicle was loaded with 70 N in the superior and posterior directions, and the magnitudes of displacement were measured. RESULTS: The amounts of superior displacement averaged 3.7 mm (stage 0), 3.8 mm (stage 1), 8.3 mm (stage 2), and 9.5 mm (stage 3). Superior displacement >50% of the AC joint was observed in stage 2 (4/6; 67%) and stage 3 (6/6; 100%). The magnitudes of posterior displacement were 3.7 mm (stage 0), 3.7 mm (stage 1), 5.6 mm (stage 2), and 9.8 mm (stage 3). Posterior displacement >50% of the AC joint was observed in stage 3 (1/6; 17%). CONCLUSION: We found that the AC ligaments contribute significantly to AC joint stability, and superior displacement >50% of the AC joint can occur with AC ligament tears alone. CLINICAL RELEVANCE: The AC ligament plays an important role not only in horizontal stability but also in vertical stability of the AC joint.

Robust method to create a standardized and reproducible atrophic non-union model in a rat femur.

OBJECTIVE: No evidence exists about which biological approach is more reliable for creating non-union model. We investigated how to create a reproducible atrophic non-union model in a rat femur. METHODS: We compared three groups: simple osteotomy (group A), partial periosteum cauterization (group B), and extensive periosteum and bone marrow resection (group C). RESULTS: All samples in group C demonstrated atrophic non-union in radiological, histological, and biomechanical analyses, however half of the samples in group B showed fracture healing at week 16. CONCLUSION: Extensive resection of periosteum and bone marrow is important for a reproducible atrophic non-union model in a rat femur.

Vascularized pedicled bone graft from the distal radius supplied by the anterior interosseous artery for treatment of ulnar shaft nonunion: An anatomical study of cadavers and a case report.

BACKGROUND: A vascularized distal radius graft can be a reliable solution for the treatment of refractory ulnar nonunion. The aim of this study is to establish the anatomical basis of a vascularized bone graft pedicled by the anterior interosseous artery and report its clinical application, using cadaveric studies and a case report. METHODS: Fourteen fresh frozen cadaveric upper limbs were used. The branches of the anterior interosseous artery (the 2, 3 intercompartmental supraretinacular artery and the fourth extensor compartment artery) were measured at the bifurcation site. The anatomical relationship between the anterior interosseous artery and motor branches of the posterior interosseous nerve was investigated. An anterior interosseous artery pedicled bone flap was used in a 48-year-old woman with refractory ulnar nonunion. RESULTS: There were two variations depending on whether the 2,3 intercompartmental supraretinacular artery branched off distally or proximally from the terminal motor branch of the posterior interosseous nerve. The proximal border of the graft was located at an average of 10.5 cm (range, 6.5-12.5 cm) from the distal end of the ulnar head in the distal type (57%) and 17.5 cm (range, 9.5-21.5 cm) in the proximal type (43%). In the clinical application, successfully consolidation was achieved 4 months post-surgery. The patient had not developed any postoperative complications until the 2-year postoperative follow-up. CONCLUSIONS: The anterior interosseous artery-pedicled, vascularized distal radius bone graft would be a reliable alternative solution for the treatment of an ulnar nonunion located within the distal one-third of the ulna.

Dorsal Intercarpal Ligament Preserving Arthrotomy and Capsulodesis for Scapholunate Dissociation.

Carpal instability secondary to scapholunate (SL) ligament tears can lead to a significant disability of the wrist. Different surgical procedures have been proposed to treat SL instability. A variety of dorsal capsulodesis techniques tethering the scaphoid have been used in patients with SL dissociation. We report a novel technique of modified dorsal intercarpal ligament (DICL) capsulodesis for the treatment of SL dissociation. The surgical indication for this procedure is complete SL ligament tear with a reducible carpal malalignment and no secondary osteoarthritis. This procedure is indicated when the remnant of torn ligament in the dorsal SL interosseous space is available for repair. First, carpal malalignment is corrected and the scaphoid and the lunate are temporarily fixed with a transosseous screw or Kirschner wires. Using a dorsal approach, the DICL is then exposed, which originates from the triquetrum and attaches to the scaphoid, trapezium, and trapezoid. The distal and proximal borders of the ligament are identified and elevated without detaching the attachment sites. The DICL is transferred proximally to reinforce the dorsal SL interosseous ligament. The wrist joint is immobilized for 3 weeks postoperatively, and dart-throwing motion is permitted until temporary SL fixation is removed at 2 to 3 months after surgery. A wrist brace is recommended until 3 to 6 months after the first surgery depending on the patient's occupation and sports activity.

Effect of soft tissue injury and ulnar angulation on radial head instability in a Bado type I Monteggia fracture model.

The effects of soft tissue damage and ulnar angulation deformity on radial head instability in Monteggia fractures are unclear. We tested the hypothesis that radial head instability correlates with the magnitude of ulnar angular deformity and the degree of proximal forearm soft tissue injury in Bado type I Monteggia fractures.We performed a biomechanical study in 6 fresh-frozen cadaveric upper extremities. Monteggia fractures were simulated by anterior ulnar angulation osteotomy and sequential sectioning of ligamentous structures. We measured radial head displacement during passive mobility testing in pronation, supination, and neutral rotation using an electromagnetic tracking device. Measurements at various ligament sectioning stages and ulnar angulation substages were statistically compared with those in the intact elbow.Radial head displacement increased with sequential ligament sectioning and increased proportionally with the degree of anterior ulnar angulation. Annular ligament sectioning resulted in a significant increase in displacement only in pronation (P < .05). When the anterior ulnar deformity was reproduced, the radial head displaced least in supination. The addition of proximal interosseous membrane sectioning significantly increased the radial head displacement in supination (P < .05), regardless of the degree of anterior ulnar angulation.Our Monteggia fracture model showed that radial head instability is influenced by the degree of soft tissue damage and ulnar angulation. Annular ligament injury combined with a minimal (5°) ulnar deformity may cause elbow instability, especially in pronation. The proximal interosseous membrane contributes to radial head stability in supination, regardless of ulnar angulation, and proximal interosseous membrane injury led to significant radial head instability in supination.

Reverse vascularized bone graft of the lateral distal humerus for non-union of the radial neck fracture: anatomical study and case report.

A few treatment options for radial neck non-union have been reported, including radial head excision, radial head replacement, and internal fixation with a bone graft. We describe a new treatment for radial neck non-union using a reverse vascularized bone graft of the lateral distal humerus. In the anatomical study, the posterior radial collateral artery (PRCA) was dissected in eight fresh-frozen cadaver arms. The number of branches from the PRCA to the humerus was determined, and the distances from these branches to the lateral epicondyle of the humerus were measured. We then used this information to create a reverse vascularizedhumeral bone graft, which was used to treat non-union of a radial neck fracture in a 73-year-old female. There were two to four PRCA branches (mean: 3.3) entering the bone. The distance from the branches to the lateral epicondyle of the humerus ranged from 2.5 to 10.8 cm. The mean distances from the most proximal and distal PRCA branches to the lateral epicondyle of the humerus were 7.6 cm and 3.4 cm, respectively. The case of non-union of a radial neck fracture was successfully treated with a reverse vascularized humeral bone graft. There were no major complications, and radiographs showed bony union at 8 weeks postoperatively. This procedure may become a new option for the treatment of non-union of fractures of the radial head and neck, as it enables preservation of the radial head, which is an important structure in the elbow and proximal radioulnar joints.

Vascularized medial femoral condyle graft for nonunion after failed radiolunate arthrodesis.

Since the medial femoral condyle flap was originally described in 1989, the indications for use of this versatile flap as a graft have broadened. We used this procedure in a patient with nonunion after failed arthrodesis of the radiolunate joint. Early bone union was achieved, with marked postoperative improvement in VAS and DASH scores.

Predictors of Hand Dexterity after Single-Digit Replantation.

BACKGROUND: Microsurgical replantation of the thumb and digits has become an increasingly familiar technique in clinical practice worldwide. However, successful digit replantation does not always provide better hand function than revision amputation. Little information is available regarding predictors of motor skill activities of replanted hands. Therefore, we retrospectively evaluated hand dexterity after single-digit replantation at a minimum follow-up of 1 year and analyzed the factors influencing dexterity. METHODS: This retrospective cohort study included 23 patients treated for amputation injuries at our institution from 2014 to 2015. Patients with amputations from Tamai's zone 2 to 5 of the thumb (3 patients), index finger (11 patients), or middle finger (9 patients) who underwent digital replantation surgery and were followed up for more than 1 year were included. Follow-up evaluations were conducted at an average of 23 months postoperatively (range: 13-25 months). We hypothesized that possible factors influencing hand dexterity after single-digit replantation were patient age, injured finger, key pinch strength, Semmes-Weinstein test result, and percentage of total active motion. Relationships between the outcome variable, which was the result of the Purdue Pegboard Test of hand dexterity, and explanatory variables were analyzed using Spearman's correlation coefficient. A p-value of < 0.05 indicated statistical significance. RESULTS: No postoperative complications occurred. Univariate analysis indicated that decreased hand dexterity after single-digit replantation was significantly associated with older age (p = 0.001) and poor recovery of sensation, as shown by the Semmes-Weinstein test (p = 0.012). CONCLUSION: Patient age was a risk factor for low hand dexterity after replantation surgery. Recovery of finger sensitivity enhanced dexterity of motor skill activities following finger replantation surgery.

Arthroscopic Distal Scaphoid Resection for Isolated Scaphotrapeziotrapezoid Osteoarthritis.

PURPOSE: To investigate the radiographic and clinical results of arthroscopic distal scaphoid resection for isolated scaphotrapeziotrapezoid (STT) osteoarthritis and analyze the radiographic parameters associated with the functional outcomes. METHODS: From 2008 to 2014, 17 wrists with symptomatic isolated STT osteoarthritis without carpal deformity underwent arthroscopic distal scaphoid resection. We evaluated visual analog scale (VAS) scores for pain, grip strength, pinch strength, and Patient-Rated Wrist Evaluation (PRWE) scores before surgery and at the final follow-up. We analyzed correlations between the resection height and the radiographic and functional outcomes. RESULTS: The average follow-up period was 42 months. The average VAS score improved from 6.1 ± 2.3 before surgery to 1.7 ± 1.9 after surgery. The average grip strength improved from 18 ± 6 to 19 ± 9 kg, pinch strength from 2.5 ± 1.1 to 4.4 ± 1.7 kg, and PRWE score from 52 ± 23 to 32 ± 24. Carpal deformity (C-L angle of > 15°) was seen in 2 patients at the final follow-up. The deformity was more likely to occur when the resection height was greater than 3 mm. CONCLUSIONS: Arthroscopic distal scaphoid resection alone can reduce pain and improve functional outcomes for early to mid-stage isolated STT osteoarthritis in patients without dorsal intercalated segment instability deformity. Resection of greater than 3 mm of the distal scaphoid may result in carpal malalignment. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Reconstruction of a metacarpal head defect due to bite injury: two case reports.

We present two rare cases of acute osteomyelitis after bite injury that were reconstructed with a third metacarpal base osteoarticular flap and a vascularised medial femoral trochlea osteocartilaginous flap. The outcomes show that a vascularised osteoarticular flap is a good treatment option for a metacarpal head defect.