Published papers

Purpose: The aim of this study was to determine the potential mechanism of implant fracture using 3-dimensional motion analysis of patients with rheumatoid arthritis. Methods: Active flexion motion in 9 hands (34 fingers) of 6 female patients with rheumatoid arthritis who previously underwent hinged silicone metacarpophalangeal joint arthroplasty was examined using 4-dimensional computed tomography. Positions of the proximal phalanges relative to the metacarpals were quantified using a surface registration method. The deformation of the silicone implant was classified in the sagittal plane in the maximum flexion frame. The longitudinal bone axis of the proximal phalanx and the helical axis of the proximal phalanx were evaluated in 3-dimensional coordinates based on the hinge of the silicone implant. Results: Nineteen fingers were classified into group 1, in which the silicone implant moved volarly during flexion without buckling of the distal stem. Twelve fingers were classified into group 2, in which the distal stem of the silicone implant buckled. Three fingers were classified into group 3, in which the base of the distal stem had already fractured. Quantitatively, the longitudinal bone axes of the proximal phalanges were displaced from dorsal to volar in the middle stage of flexion and migrated in the proximal direction in the late phase of flexion. The helical axes of the proximal phalanges were located on the dorsal and proximal sides of the hinge, and these tended to move in the volar and proximal directions as the metacarpophalangeal joint flexed. Conclusions: Volar and proximal translation of the proximal phalange was observed on 4-dimensional computed tomography. Clinical relevance: Proximal displacement of the bone axis late in flexion appears to be a contributing factor inducing implant fractures, because the pistoning motion does not allow the implant to move in the proximal direction.

Objective: CT imaging precisely and quantitatively analyzes the kinematics of the carpal bones to evaluate the etiology of related osteoarthritis. Previous studies have investigated the kinematics of the trapeziometacarpal joint using static CT scans of various postures including the pinch position. This study analyzed the in-vivo kinematics of the trapeziometacarpal joint during dynamic pinch motion in young healthy volunteers using four-dimensional CT. Materials and methods: Twelve healthy young volunteers participated in this study. Each participant held the pinch meter between their thumb and index finger and pinched it with maximum force for a period of 6 s. This series of movement was recorded using a four-dimensional CT. The surface data of the trapezium and first metacarpal of all frames were reconstructed, and bone movement at the trapeziometacarpal joint was calculated using sequential three-dimensional registration. The instantaneous pinch force of each frame was measured using a pointer on a pinch meter that was reconstructed from the CT data. Results: The first metacarpal was abducted (15.9 ± 8.3°) and flexed (12.2 ± 7.1°) relative to the trapezium, and significantly translated to the volar　(0.8 ± 0.6 mm) and ulnar directions (0.9 ± 0.8 mm) with maximum pinch force. This movement consistently increased with the pinch force. Conclusion: This study successfully employed 4D-CT to precisely demonstrate changes in rotation and translation at the trapeziometacarpal joint during pinch motion for various instantaneous forces.

Background: This study aimed to clarify the influence of preoperative electrodiagnostic (EDX) utilisation and its severity on surgically treated patients with carpal tunnel syndrome (CTS). Methods: This retrospective study analysed the data of patients who underwent CTS surgery at our facility from 2012 to 2022. Data regarding age, sex, affected side, diabetes mellitus, rheumatoid arthritis, haemodialysis and insurance type were collected, along with the following clinical information: utilisation of EDX, steroid injection, number of items of preoperative physical examination and history taking, intervals between symptom onset and the initial visit and between the initial visit and surgery, type of surgical procedure and surgery categorisation (primary or revision). EDX data (EDX severity, interval between EDX and surgery and concomitant nerve lesions) were also investigated. Univariate and multivariate analyses were conducted to assess the influence of EDX utilisation and severity on clinical parameters. Results: Of the 343 hands enrolled in our study, 304 (89%) underwent preoperative EDX assessment. EDX severity was classified as normal, mild, moderate or severe in 6 (2%), 18 (6%), 102 (34%) and 178 hands (58%), respectively. After the univariate and multivariable analyses, more items of preoperative physical examination and history taking were associated with non-EDX utilisation, whereas younger age, female sex and steroid injection were associated with milder EDX. Conclusions: Increased number of items of preoperative physical examination and history taking or steroid injection were independently associated with non-EDX utilisation or milder EDX, respectively, suggesting that when thorough clinical evaluation is conducted, hand surgeons may be less likely to request for EDX before surgery. Moreover, their treatment recommendation may be influenced by EDX severity. Level of Evidence: Level III (Diagnostic)

Background:Corrective osteotomy for intra-articular malunion is a challenging procedure. However, recent advancements, including patient-matched instruments created on the basis of preoperative computer simulation, enable accurate intra-articular correction. We hypothesized that intra-articular corrective osteotomy using patient-matched instruments for the treatment of distal radial intra-articular malunion would reduce intra-articular deformity and restore wrist function at 12 months of follow-up.Methods:This prospective study included 12 patients with distal radial intra-articular malunion who underwent intra-articular corrective osteotomy external to the joint using patient-matched instruments. The primary end point was the maximum step-off on the articular surface of the distal radius, measured with use of computed tomography (CT), with an expected postoperative value of ≤1.5 mm. The secondary end points included the gap of the articular surface; range of motion; grip strength; pain evaluated using a visual analog scale (VAS); patient satisfaction; Disabilities of the Arm, Shoulder and Hand (DASH) score; and Patient-Rated Wrist Evaluation (PRWE) score. A mean postoperative step-off of ≤1.5 mm for the primary end point was assessed with use of the 1-sample t test. The secondary end points were assessed with use of the Dunnett multiple comparison test.Results:The average step-off significantly improved from 3.75 ± 1.04 mm preoperatively to 0.51 ± 0.40 mm at the 52-week postoperative follow-up and was maintained within 1.5 mm. The average wrist and forearm range of motion, VAS score, grip strength, DASH score, and PRWE score significantly improved. Eleven patients were either very satisfied or satisfied with their outcomes.Conclusions:The use of patient-matched instruments could contribute to improving postoperative outcomes of intra-articular corrective osteotomy procedures involving the distal radius.Level of Evidence:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Case:We present a 28-year-old woman with long-standing left ulnar wrist pain. Physical examination revealed severe tenderness over the pisiform; imaging findings were normal. Surgical exploration revealed compression of an aberrant branch, likely Kaplan's accessory branch, around the pisiform. Complete symptom relief was achieved after nerve decompression.Conclusion:Clinical symptoms associated with Kaplan's accessory branch are rare, indicating that many branches may be asymptomatic or overlooked despite the presence of symptoms. Kaplan's accessory branch should be considered as a potential differential diagnosis for refractory ulnar wrist pain.

Aims This study aimed to evaluate the mid-term clinical outcomes, complications, and survival rates of the unlinked K-NOW (Teijin Nakashima Medical, Japan) total elbow arthroplasty (TEA), focusing on the use of cementless fixation. Methods This retrospective study included 41 elbows in 37 patients who underwent primary TEA using unlinked K-NOW between April 2012 and March 2021, with a minimum follow-up of two years. Surgical approaches included the lateral paraolecranon (LPO) and triceps-off approaches. Clinical evaluations included range of motion (ROM) and Mayo Elbow Performance Score (MEPS). Complications were recorded, and Kaplan-Meier survival analysis was performed, with aseptic loosening and revision surgery as endpoints. Results The mean patient age was 68.4 years (SD 11.6), and the mean follow-up period was 4.7 years (2.1 to 10.1). The LPO approach was used in 35 elbows (85.4%), and cementless fixation was applied to 41 humeral components (100%) and 35 ulnar components (85.4%). Among patients with ≥ five years of follow-up (n = 16), significant improvements were observed in ROM (extension, from -38° to -19°; flexion, from 107° to 130°; pronation, from 55° to 72°; supination, from 62° to 73°; p < 0.001), and MEPS (from 48 to 93 points; p < 0.001) at five years postoperatively. Complications occurred in six elbows (14.6%): three elbows (7.3%) with aseptic loosening and three elbows (7.3%) with periprosthetic fractures; no postoperative dislocation was observed. Revision surgeries were required in two elbows (4.9%). Kaplan-Meier survival rates were 92.7% (95% CI 84.7 to 100) at five years for loosening, and 97.1% (95% CI 91.4 to 100) at five years for revision. All aseptic loosening occurred within three months postoperatively. Conclusion The unlinked K-NOW with cementless fixation, mostly using the LPO approach, demonstrated favourable outcomes with improved ROM and MEPS, a low complication rate, and promising survival. In cases with severe osteoporosis or bone-implant instability, cemented fixation or a triceps-off approach may help reduce the risk of early complications.

A 40-year-old patient and a 45-year-old patient presented with chronic dorsal and lateral subluxation of the proximal interphalangeal (PIP) joint of the little finger and underwent surgeries. Through a dorsal approach, the ulnar lateral band was transected and transferred to the radial side through the volar side of the PIP joint. The transferred lateral band and the remnant of the radial collateral ligament were secured with an anchor on the radial side of the proximal phalanx. Satisfactory results were obtained without the loss of flexion and recurrence of subluxation of the finger. This method enabled the correction of both dorsal and lateral instability of the PIP joint through a dorsal incision. The modified Thompson-Littler technique was useful for chronic instability of the PIP joint.

Wrist arthroscopy is now widely indicated for diagnosis and treatment of acute or chronic wrist pain, especially for triangular fibrocartilage complex (TFCC) lesions, as a gold standard. In most cases radiocarpal and midcarpal arthroscopy was performed, while DRUJ arthroscopy has been rarely performed because of its difficulties. Recent anatomic and biomechanical studies demonstrated that the radioulnar ligament (RUL), which is the proximal component of the TFCC facing to the DRUJ, is the primary stabilizer of the distal radioulnar joint (DRUJ). Rupture of the radioulnar ligament (RUL) at the fovea area, where it is the main attaching portion to the ulna and is the isometric point during forearm rotation as the rotation axis passes, is responsible for DRUJ instability. Although physical examination and imaging diagnosis may indicate a foveal detachment of the TFCC, DRUJ arthroscopy is potential for visualizing the RUL at the fovea. Role of DRUJ arthroscopy should be more important not only for diagnosis of rupture of the RUL but also for decision making of treatment option for RUL tear. DRUJ arthroscopy also demonstrates the joint surface of both the sigmoid notch and ulnar head, and the proximal surface of the TFCC.

PURPOSE: To assess the outcomes of our technique involving oblique headless compression screw for arthrodesis of the thumb interphalangeal joint and the distal interphalangeal joints of the other digits. METHODS: A total of 28 joints (19 thumb interphalangeal and 9 distal interphalangeal) in 23 patients with a mean age of 65 years (range, 58-74 y) were retrospectively analyzed. All operations were performed with the Acutrak2 micro-screw. After the resection of synovium and joint cartilage by a dorsal approach, a 0.88-mm diameter guide wire was inserted at the ulnar side of the proximal phalanx in the thumb and radial side of the middle phalanx in the other digits from proximal to distal to fix the joint obliquely. We verified its position under fluoroscopic control and placed the cannulated screw from proximal to distal over the guide wire. RESULTS: Intraoperative rigid fixation was obtained except for 1 case, which required additional K-wire fixation. The overall union rate was 96%. Average time to fusion was 11 weeks (range, 8-30 wk), with 76% achieving union within 3 months. There were 2 complications, 1 nonunion and 1 late infection. Other complications such as dorsal skin necrosis, nail deformity, and paresthesia did not occur. CONCLUSIONS: Efforts to avoid invasion of the nailbed can be technically demanding. We believe that our proximal to distal technique with oblique placement of the headless compression screw is a straightforward and effective method with a relatively low risk of complication. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

PURPOSE: To retrospectively analyze consecutive cases with opening wedge corrective osteotomy of the volarly malunited distal radius with iliac bone graft, including preoperative and postoperative comparison of symptoms, visual analog scale (VAS), Japanese Society for Surgery of the Hand version of the Disabilities of the Arm, Shoulder, and Hand (DASH-JSSH) questionnaires, radiographic indices, clinical results as evaluated by modified Mayo wrist score, and complications. METHODS: Subjects were 28 patients with volarly malunited distal radius fracture treated by transverse opening wedge osteotomy with oblique iliac bone graft. Preoperative symptoms included wrist deformity, weakness of grip strength, and marked restriction of supination range. Postoperative symptoms, radiographic parameters, clinical results, and complications were analyzed at an average of 25 months of follow-up. We also analyzed the union period of the radius in younger patients (< or =45 years old) and older patients (>45 years old). RESULTS: Mean preoperative visual analog scale was 45, improving significantly to 3 postoperatively. Range of wrist motion improved in all 28 patients, with supination range improving from 16 degrees preoperatively to 80 degrees postoperatively. Mean preoperative DASH-JSSH score was 55, improving to 9 postoperatively. Radiography revealed that volar tilt improved from 32 degrees preoperatively to 10 degrees postoperatively, and radial inclination increased from 17 degrees to 21 degrees . Preoperative ulnar variance of +5.9 mm was corrected to -0.1 mm postoperatively. All 28 wrists demonstrated bony union at the osteotomy site after an average of 52 days (younger patients, 51 days; older patients, 54 days). No complications, significant radiographic correction loss, or nonunion were seen after at least 2 years of follow-up. Modified Mayo wrist score was excellent in 16 patients, good in 10 patients, and fair in 2 patients. CONCLUSIONS: Opening wedge osteotomy for volarly malunited distal radius fracture restored bony configuration of the distal radius, decreased pain, and improved grip strength and range of wrist motion, particularly for forearm supination. No complications or noteworthy correction loss were noted after surgery, even in older patients. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

OBJECTIVE: Polymorphisms and haplotypes of the peptidylarginine deiminase type 4 gene (PADI4) have been reported to be associated with rheumatoid arthritis (RA) in a Japanese population. However, subsequent replication studies showed conflicting results. The aim of this study was to determine whether meta-analysis would prove the existence of the association. METHODS: PubMed was searched using the term 'PADI4' for articles from the publication of the first study to December 2005. Replication studies that tested the association between PADI4 and RA were reviewed for meta-analysis. The Breslow-Day test for homogeneity across the studies was calculated. The Mantel-Haenszel procedure was used to pool odds ratios (OR) with 95% confidence intervals (CI) to evaluate the association. RESULTS: Six replication studies, one from Japan and five from Europe and North America, fulfilled the selection criteria for inclusion in the meta-analysis. Homogeneity was confirmed across the replication studies. The common OR was 1.14 (95% CI = 1.07-1.21) for allelic distribution. The association was confirmed when only five replication studies in the European descent populations were combined (P = 0.0096, common OR = 1.10). CONCLUSIONS: Our meta-analysis showed a positive association between PADI4 and RA not only in the Japanese population but also in populations of European descent.

Calcific periarthritis or calcific tendinitis occurs most frequently in the shoulder and rarely in the elbow. Cimetidine was previously reported to be effective for chronic calcific periarthritis of the shoulder. Here, we present five patients with chronic calcific periarthritis of the elbow treated by administration of cimetidine; there were six affected elbows in these five patients. Although all patients had been treated with nonsteroidal anti-inflammatory drugs for at least 3 months, their symptoms were not relieved. All patients took oral administration of cimetidine 400 mg daily. The pain was completely relieved in an average of 1.8 months after the administration of cimetidine, and the calcification of the elbow disappeared in an average of 5.1 months. During the follow-up period, there were no symptoms suggesting a recurrence. Although the detailed mechanism of action of cimetidine on periarticular calcifications remains to be understood, cimetidine appears to be a potential therapeutic agent for chronic calcific periarthritis.

OBJECTIVE: This retrospective study was designed to evaluate the outcomes of four different surgical reconstructions for extensor tendon ruptures in ulnar three fingers in 48 patients with rheumatoid arthritis. METHODS: The following four techniques were performed; palmaris longus tendon grafting (PL group; n = 9), extensor indicis proprius (EIP) tendon transfers (EIP group; n = 8), end-to-side transfers with tension-reduced early mobilization (End-to-side group; n = 16), and a combination of end-to-side and EIP transfers (Combination group; n = 15). Loss of extension was evaluated to determine the mean postoperative range of motion of the metacarpophalangeal (MP) joint and clinical outcomes were categorized using modified Geldmacher criteria. RESULTS: Combination group demonstrated the best mean MP joint extension (-3 degrees ), followed by End-to-side group (-12 degrees ), EIP group (-16 degrees ), and PL group (-21 degrees ). Combination group yielded the best clinical outcomes with all cases showing good results. CONCLUSIONS: The combination of end-to-side and EIP transfer was an effective surgical reconstruction procedure for triple fingers extension loss.

© 2018 Journal of Shoulder and Elbow Surgery Board of Trustees Hypothesis: Three-dimensional (3D) surgical planning for unlinked total elbow arthroplasty (TEA) would be helpful for estimation of the implant size and accurate placement of implants. Methods: We included 28 patients who underwent TEA with an unlinked total elbow implant in this study. All patients underwent computed tomography scans of the elbow before surgery, and a 3D digital model of the elbow was reconstructed. After the appropriate size and position of the prosthesis were determined, 10 points around the bone tunnel (4 on the humerus and 6 on the ulna) were measured to plan the insertion of the humeral and ulnar stems. Two-dimensional planning was also performed using anteroposterior and lateral radiographs. Intraoperatively, the surgeon measured the planned parameters using a slide gauge to reproduce the 3D planned position of the stem insertion. Results: The stem sizes were accurately estimated in 57% of patients for the humerus and 68% for the ulna with 2-dimensional planning and in 86% for the humerus and 96% for the ulna with 3D planning. The mean differences between the positions of the prostheses after surgery with reference to the planned positions were 0.8° of varus and 1.5° of flexion for the humeral component and 0.7° of varus and 2.9° of flexion for the ulnar component. We did not evaluate rotational positioning in this study. Conclusions: The 3D surgical planning allowed accurate estimation of the implant size and appropriate placement of implants. This method may contribute to a reduced incidence of complications and improved long-term outcomes from TEA.

Copyright © 2018 By The Journal Of Bone And Joint Surgery, Incorporated. Background: Costal osteochondral grafting is a technique to achieve anatomical and biological repair of articular defects. Some small series of clinical applications of this procedure for advanced osteochondritis dissecans of the humeral capitellum, with short-term follow-up, have been reported; however, longer-term outcomes remain unclear. The purpose of this study was to clarify longer-term clinical outcomes of costal osteochondral autografts in the treatment of advanced osteochondritis dissecans of the humeral capitellum. Methods: Seventy-two patients with an osteochondral defect of the humeral capitellum were treated with costal osteochondral autograft and followed for a minimum of 3 years (mean follow-up, 57 months; range, 36 to 147 months). The mean patient age was 14.3 years. Clinical outcomes, including elbow range of motion, Timmerman and Andrews clinical rating score, donor-site morbidity, responses to a questionnaire regarding a return to sporting activities, and radiographic findings, were evaluated. Results: The mean elbow range of extension/flexion increased significantly, from 221/122 preoperatively to 24/ 136 postoperatively (p < 0.001). The mean clinical rating score improved significantly, from 101 to 190 by the latest follow-up (p < 0.001). The overall clinical score-based assessment was excellent for 60 patients, good for 9, and fair for 3. Seventy of the 72 patients returned to their original sport. The remaining 2 patients had changed sporting activities before surgery and did not return to baseball, despite satisfactory clinical results. Conclusions: Costal osteochondral autograft successfully achieved anatomical and biological reconstruction in the treatment of advanced osteochondritis dissecans of the humeral capitellum.

Purpose This study aimed to evaluate the clinical outcomes of surgical treatment for chronic mallet injury with severe extension lag using an anatomic reconstruction of the terminal tendon and lateral band with a palmaris longus (PL) tendon graft. Methods Eleven patients with a mean age of 52 years (range, 24–82 years) who underwent surgical reconstruction for chronic tendon mallet injuries using the PL tendon were included. The harvested PL tendon was either folded longitudinally or divided into two slips. The graft was secured to the distal phalanx using a bone anchor and sutured to the soft tissues and remnants of the original terminal tendon distal to the distal interphalangeal (DIP) joint. Each half-slip tendon was passed under the transverse retinacular ligament and sutured side-to-side to the lateral band at approximately the midpoint of the proximal phalanx. The active range of motion of the affected finger was evaluated before and after surgery, and any complications were recorded. Results Before surgery, the extension of the DIP joint averaged −49.5° (range, −40° to −60°). The postoperative mean lag of the DIP joint improved to −7.8° (range, −20° to +20°). According to the Miller classification, four patients had excellent results, four had good results, and three had fair results. Two patients who underwent folded-PL tendon grafting developed superficial dorsal skin infections on the little finger that resolved with oral antibiotics or removal of the sutures. Conclusions Anatomical reconstruction of the terminal tendon and lateral bands using a PL tendon graft yielded satisfactory outcomes in chronic tendon mallet injuries. Dividing the PL tendon into two slips is recommended to reduce the risk of postoperative infection. Type of study/level of evidence Therapeutic IV.

Case:A 77-year-old man with an acromioclavicular joint ganglion cyst with cuff tear arthropathy had a large mass in the left shoulder. Arthroscopic distal clavicle resection successfully relieved his symptoms without loss of shoulder function by enlargement of the bypass between the cyst and subacromial space through the acromioclavicular joint.Conclusion:Arthroscopic distal clavicle resection can remove a 1-way check valve in a minimally invasive manner. This case indicated that arthroscopic distal clavicle resection could be a useful treatment option for patients with acromioclavicular joint ganglion cysts with functional but irreparable rotator cuff tears.

Case:A 73-year-old woman presented with wrist pain and loss of extension in the middle and ring fingers. Radiography revealed a dorsally displaced lunate fragment, resulting in a diagnosis of Kienböck disease with extensor tendon rupture. Artificial lunate replacement and tendon transfer were performed as treatment. Two years postoperatively, the pain was relieved, and the extension lag was 0°. The wrist motion and carpal height had also improved.Conclusion:Lunate excision, partial wrist arthrodesis, or proximal row carpectomy are known treatments for Kienböck disease with extensor tendon rupture. Lunate arthroplasty is a novel, useful treatment option for this condition.