Kinematic Investigation of Healthy, Arthritic, and Postsurgery Thumbs: Is the Metacarpophalangeal Joint the Gateway to Carpometacarpal Arthritis?

The thumb carpometacarpal (CMC) joint is one of the most likely joints to develop osteoarthritis (OA). If conservative treatments fail to alleviate symptoms, surgery may be pursued. Kinematic outcomes of CMC surgery techniques have been described, but current tools have limitations in capturing motion abilities. The goals of this study were (1) develop a new and robust set of kinematic outcome measures, and apply them to (2) a cohort of younger and older control individuals without CMC OA to determine age and sex-related changes, and (3) a cohort of participants with CMC OA before, 3 months, and 6 months after undergoing thumb ligament reconstruction with tendon interposition surgery to detect the impacts of surgery. 52 (26 males, 26 females) control and 18 (3 males, 15 females) surgical participants were tested. Kinematics were investigated using motion capture by mapping the three-dimensional motion space of the whole thumb, and two-dimensional motion boundaries of the metacarpal (MC) and proximal phalange (PP). Visual analog pain score was recorded. Older control participants had shifted regions of motion compared to younger participants (p ≤ 0.027), suggesting asymptomatic CMC wear. Control females had 31% more metacarpophalangeal (MCP) motion than control males (p = 0.013), which could alter loading paths through the CMC joint and increase OA risk. Pain at 6 months postsurgery was 72% less than presurgery (p < 0.001), but motion abilities were 20-28% less than presurgery (p ≤ 0.074) and 24-40% less than control participants (p ≤ 0.066). These techniques have the possibility of identifying presymptomatic motion changes, including those at the metacarpophalangeal joint in CMC OA progression.

High Fracture Rate of AVANTA Silicone Implant Following Arthroplasty of the Thumb MCP Joint of Rheumatoid Arthritis Patients with Boutonniere Deformities.

We retrospectively investigated the mid-term outcomes of arthroplasty using the AVANTA silicone implant for thumb metacarpophalangeal (MCP) joints with boutonniere deformity in patients with rheumatoid arthritis (RA). This study involved 36 thumbs of 33 RA patients with a mean follow-up period of 5.1 years (range, 2.0-13.3). Postoperatively, the mean extension was significantly increased and the mean flexion was significantly decreased (p<0.001, p<0.001, respectively), resulting in the mean arc of range of motion (ROM) shifting in the direction of extension after surgery. Implant fracture was observed in 10 thumbs (28%), and 4 of these (11%) underwent revision surgery. The survivorship with implant fracture and revision surgery as endpoints were 73.4% and 91.8% at 5 years, respectively. The preoperative arc of ROM and the postoperative flexion range of the implant-fracture group were significantly greater than those in the no-implant-fracture group (p=0.039, 0.034, respectively). These results suggest the importance of patient education and careful rehabilitation to prevent excessive flexion. Overall, the AVANTA silicone implant showed a relatively high rate of implant fracture at our institute.

Does Preservation of Metacarpophalangeal Joint Vascularity Protect Against Physeal Arrest in Index Finger Pollicization?

PURPOSE: To determine whether preservation of blood supply to the index metacarpophalangeal joint decreases the rate of physeal arrest. METHODS: A retrospective review of 41 pollicized digits in 35 patients with 2-year minimum radiographic follow-up was conducted at a single institution. Other complications evaluated included nonunion at the pollicized digit base and clinical instability at the new carpometacarpal joint. Findings were compared to historical controls, which were performed by our group prior to routine identification and sparing of the metacarpophalangeal joint blood supply. No other modifications to surgical technique were made between the previous and current patient cohorts. RESULTS: Two pollicized digits in two different patients had radiographic evidence of physeal arrest, one of which was partial and the other complete, for an arrest rate of 4.9%. This was significantly less than the arrest rate in our historical cohort of 24.7% (21 of 85 patients). Five patients did not have radiographic bony union at the base of the index metacarpal, but only one patient had clinical instability at the new carpometacarpal joint. CONCLUSIONS: Significantly fewer patients who underwent index finger pollicization with preservation of the metacarpophalangeal joint blood supply went on to develop physeal arrest when compared to patients who underwent pollicization prior to adoption of this technique. This finding suggests that sparing of the physeal blood supply is preventative against proximal phalanx physeal arrest. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Long-Term Implant Fracture Rates Following Silicone Metacarpophalangeal Joint Arthroplasty in Rheumatoid Arthritis.

PURPOSE: The primary objective of this study was to compare the long-term survival rates of silicone metacarpophalangeal (MCP) arthroplasties between two major implants in patients with rheumatoid arthritis, using implant fracture as an end point. We also evaluated the difference in postoperative function between patients with fractured and intact implants as a secondary objective. METHODS: A retrospective cohort study was conducted on 372 fingers of 133 hands that underwent silicone MCP arthroplasty between January 2000 and June 2019 (mean follow-up, 7.6 years). The survival rates of Swanson-type and Sutter-type implants were compared, using implant fracture as the end point after a radiographic evaluation. Clinical measures and upper limb functional assessments using the Disabilities of the Arm, Shoulder, and Hand (DASH) score were performed in the nested cohort. RESULTS: The 10.6-year survival rates for implant fracture of Swanson- and Sutter-type implants were 86.2% and 9.4%, respectively, with significantly higher survival noted for Swanson-type implants. The Sutter-type implant showed increased susceptibility to fracture in all four fingers compared to the Swanson-type implant. Implant fractures were primarily observed at the stem-hinge junction. There were no significant differences in upper limb function between the fractured and intact implant groups. CONCLUSIONS: Sutter-type implants were found to be more prone to fracture compared with Swanson-type implants. However, implant fractures did not significantly affect upper limb function. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognosis IV.

Biological Versus Nonbiological Reconstruction of the Ulnar Collateral Ligament of the Thumb Metacarpophalangeal Joint: A Retrospective Study.

PURPOSE: The purpose of this study was to compare clinical and radiologic outcomes of biological ligament reconstruction (BLR) versus nonbiological ligament reconstruction (NBLR) for chronic injuries involving the ulnar collateral ligament of the thumb's metacarpophalangeal joint. METHODS: Forty-two patients who underwent static BLR (n = 24) or NBLR (n = 18) were included in this retrospective analysis. Preoperative, postoperative, and contralateral thumb measurements (clinical evaluation, radiographs, and subjective outcome questionnaires) were compared over a mean of 38 months of follow-up. RESULTS: Average postoperative thumb metacarpophalangeal and interphalangeal joint ranges of motion were 2° to 54° and 0 to 71°, respectively, for BLR and 0° to 58° and 0° to 71°, respectively, for NBLR. Average grip and pinch strengths, relative to the unaffected hand, were 102% and 84% versus 103% and 89%, respectively. All patients demonstrated stability with a firm end point, compared with the unaffected thumb. The average Quick Disabilities of the Arm, Shoulder, and Hand score among all patients was 12 for the disability/symptom module, 0 for the sports module, and 17 for the work module. Stiffness was reported among four patients, and no patient sustained wound-related issues or other complications. CONCLUSIONS: Nonbiological ligament reconstruction of the thumb ulnar collateral ligament generates short-term outcomes comparable with those of BLR, potentially allowing for expedited recovery and rehabilitation. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

The influence of a tension band fixation as an adjunct for arthrodesis of the metacarpophalangeal joint in the horse.

OBJECTIVES: To determine the influence of a stainless-steel cable (SSC) tension band fixation as an adjunct to a locking compression plate (LCP) for arthrodesis of the equine metacarpophalangeal (MCP) joint. STUDY DESIGN: Experimental. An ex vivo biomechanical paired equine cadaver limb study. SAMPLE POPULATION: Five MCP joint pairs were collected from adult Thoroughbred horses, euthanized for reasons unrelated to orthopedic disease. METHODS: Each pair of MCP joints were randomly implanted with either a dorsally placed 5.5 mm LCP and a palmarly placed 2.0 mm SSC or a dorsally placed 5.5 mm LCP alone. Each construct was tested in cyclic loading followed by single cycle to failure in axial compression. Displacement at a target load of 1 kN over 3600 cycles at 1 Hz was recorded prior to single cycle to failure testing. RESULTS: In cyclic testing, displacement was not significantly different between the first and last 5% of testing cycles regardless of construct. Maximum displacement of each construct during cyclic testing was <1.1 mm. In single cycle testing, the observed yield point did not reveal any difference between LCP and LCP-SSC (p = .440). The maximum load at failure was significantly higher in LCP-SSC compared to constructs with the LCP alone (p = .046). CONCLUSION: The addition of the SSC to the LCP did not statistically affect construct displacement during cyclic loading or construct yield load during subsequent single cycle to failure. CLINICAL SIGNIFICANCE: This study provided much needed information regarding the necessity of a tension band SSC application in the arthrodesis of the MCP/MTP joint in horses.

Locking of the metacarpophalangeal joint: A comprehensive review of the literature.

Locked metacarpophalangeal joint is an uncommon phenomenon with many possible etiologies. Diagnosis can be difficult because of the many more common pathologies (trigger finger, sagittal band lesion, etc.) that can lead to a clinical picture that may resemble the locked metacarpophalangeal joint. Once the differential diagnoses have been eliminated, the etiology of this blockage must be determined and the surgical procedure must be oriented. The origin of the problem is often difficult to determine, especially since standard imaging tests are often not very informative. Several clinical forms are possible, with blockages in extension or flexion, but which will have a disabling functional impact on the overall function of the hand. Currently, there is no gold standard for the management of this condition. In this study, we performed a review of the literature in order to better understand the different possible etiologies but also to analyze the different diagnostic and therapeutic management. LEVEL OF EVIDENCE: IV.

A Comparative Study of Thumb Metacarpal Morphology and Shape Categorization.

PURPOSE: To describe the shape of a biplanar thumb metacarpal (MC) head and identify how it differs morphologically from previously described flat and round MC heads. METHODS: Lateral radiographs of the thumb were collected retrospectively from our patient database. Patients were included in the study if they had an appropriate lateral radiograph, met the age criteria (range; 18-75 years), and did not have severe metacarpophalangeal (MCP) joint arthritis. Metacarpal heads were categorized as flat or round by dividing the distance measured from the volar to the dorsal edge of the articular surface by the radius of curvature of the articular surface. A ratio of 1.7 or greater indicated a round MC head, whereas a ratio of less than 1.7 indicated a flat MC head. RESULTS: Among the 210 study participants, 110 were female and the average age was 47.3 years. During the measurement and classification process, it was determined by a board-certified hand surgeon that a subset of MCs did not meet the criteria for being categorized as either flat or round because of the inability to appropriately measure the radius of curvature of the MCP joint. Of the participants 113, 79, and 18, were classified as having either round, flat, or biplanar MC head shapes, respectively. CONCLUSIONS: We have identified a third, biplanar MC head shape. The biplanar head shape is more triangular and has two distinct planes on the articular surface that converge into an apex. CLINICAL RELEVANCE: The shape of the MC head has been shown to influence the range of motion of the MCP joint which may have an influence on the types of injuries that occur at the MCP joint. Further studies are required to understand how shape classification of MC heads may be useful and relevant to range of motion and risk of injury.

Changes in the Functional Range of Motion of the Thumb Metacarpophalangeal Joint After Trapeziometacarpal Arthrodesis for Patients With Advanced Trapeziometacarpal Osteoarthritis.

PURPOSE: Advanced-stage trapeziometacarpal (TMC) osteoarthritis of the thumb often presents with concomitant hyperextension deformity of the metacarpophalangeal (MCP) joint. Although several studies have reported simultaneous procedures to correct this deformity, the indication for these procedures remains controversial. The purpose of this study was to evaluate changes in the range of motion (ROM) of the thumb MCP joint before and after TMC arthrodesis. METHODS: We evaluated the functional flexion and extension and functional ROM of the MCP joints during the performance of 10 activities of daily living tasks before and after TMC arthrodesis in 10 thumbs of 9 patients with Eaton stage III TMC osteoarthritis and hyperextension deformity of the MCP joint. RESULTS: The mean functional flexion of the MCP joint increased from 26° to 38°, and the mean functional extension of the MCP joint decreased from 16° to 5° of hyperextension. There was no change in the mean total arc of functional ROM of the MCP joint. CONCLUSIONS: The MCP joint motion shifted from extension to flexion after TMC arthrodesis, and the total arc of functional ROM of the MCP joint was similar before and after arthrodesis. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

In Vivo Metacarpophalangeal Joint Kinematics After Silicone Implant Arthroplasty in Patients With Rheumatoid Arthritis.

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.

Patient-Reported Outcomes and Function After Surgical Repair of the Ulnar Collateral Ligament of the Thumb.

PURPOSE: The purpose of this study was to report prospectively collected patient-reported outcomes of patients who underwent open thumb ulnar collateral ligament (UCL) repair and to find risk factors associated with poor patient-reported outcomes. METHODS: Patients undergoing open surgical repair for a complete thumb UCL rupture were included between December 2011 and February 2021. Michigan Hand Outcomes Questionnaire (MHQ) total scores at baseline were compared to MHQ total scores at three and 12 months after surgery. Associations between the 12-month MHQ total score and several variables (i.e., sex, injury to surgery time, K-wire immobilization) were analyzed. RESULTS: Seventy-six patients were included. From baseline to three and 12 months after surgery, patients improved significantly with a mean MHQ total score of 65 (standard deviation [SD] 15) to 78 (SD 14) and 87 (SD 12), respectively. We did not find any differences in outcomes between patients who underwent surgery in the acute (<3 weeks) setting compared to a delayed setting (<6 months). CONCLUSIONS: We found that patient-reported outcomes improve significantly at three and 12 months after open surgical repair of the thumb UCL compared to baseline. We did not find an association between injury to surgery time and lower MHQ total scores. This suggests that acute repair for full-thickness UCL tears might not always be necessary. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

Prognostic factors and clinical features in metacarpophalangeal joint hyperextension after ligament reconstruction with trapeziectomy: A retrospective cohort study.

BACKGROUND: Management of metacarpophalangeal (MCP) hyperextension deformity in thumb carpometacarpal (CMC) joint arthritis is challenging. It remains unclear how the preoperative MCP joint angle affects the outcomes. The present study aimed to clarify the associations between postoperative MCP hyperextension deformity and outcomes, and to determine the preoperative MCP joint angle that can predict poor outcomes. METHODS: We investigated the functional outcomes of patients who underwent surgery for CMC arthritis at two institutions from 2016 to 2020. All patients received a modified Thompson technique, ligament reconstruction suspension arthroplasty, and had no additional treatment for MCP hyperextension. The patients were divided into three groups according to their postoperative MCP joint angles: Group A, <10°; Group B, 10°-20°; Group C, >20°. Evaluations included preoperative and postoperative VAS, Quick DASH, range of motion (ROM), grip power, pinch strength, first web space angle, and postoperative trapezial space ratio (TSR). RESULTS: Overall, 66 eligible patients (72 thumbs) were identified and received follow-up for a mean of 25.2 months. The 72 thumbs were assigned to Group A (n = 38), Group B (n = 16), and Group C (n = 18). Group C had significantly lower preoperative MCP joint angle and postoperative grip power, pinch strength, and TSR compared with the Group A (P < 0.05). However, there were no significant differences in VAS, Quick DASH, ROM, and first web space angle (P > 0.05). The preoperative risk factor for highly residual MCP hyperextension was preoperative MCP joint angle (OR = 1.078; P = 0.001), with a cut-off value of 21.5° (AUC = 0.79; sensitivity = 0.813; specificity = 0.821). CONCLUSIONS: Postoperative MCP hyperextension of >20° after ligament reconstruction with trapeziectomy has adverse effects on functional outcomes. In cases with preoperative MCP joint angle of >21.5°, additional treatment for MCP hyperextension should be considered.

Long-term preservation of metacarpophalangeal joint function in traumatic defects by metatarsophalangeal osteochondral transplantation.

INTRODUCTION: The integrity of the metacarpophalangeal (MCP) joints is essential for finger and hand function. Preservation of range-of-motion is one of the aims in reconstruction of complex injuries to these joints. Osteochondral transplants have shown to be reliable in reconstruction of various joint defects. This series presents three patients with traumatic injuries to four MCP joints, which were reconstructed by seven avascular osteochondral transplants of metatarsophalangeal (MTP) joints. The joints were examined for radiographic signs of resorption or joint space narrowing, and if this would affect the joints' function in the long term. METHODS: In three patients (40, 45 and 48 years) with complex injuries to their MCP joints (one milling, two saw injuries), four joints were reconstructed by three metatarsal head and four osteochondral transplants of the base of the proximal toe phalanges. Beside the joint itself, various soft tissue defects were reconstructed in each patient. The patients were clinically and radiographically examined after 9, 6, respectively, 7 years. RESULTS: All patients were satisfied with the result without any pain in the MCP joints. Range-of-motion in the four affected joints rated 25, 60, 75, and 80°, DASH scores rated 13, 29, and 17, respectively. None of the patients complained of problems at their feet. Radiographic examination revealed moderate joint space narrowing in one of the four joints. In another patient, localized osteolysis was found around the screws' heads, so that the screws were removed 7 years post-op. CONCLUSIONS: Osteochondral transplants for reconstruction of MCP defects are able to preserve function in severely injured joints even in the long term. Joint space narrowing may occur, which is not accompanied by pain, however. Since localized osteolysis can cause screw head prominence, mid-term radiographic follow-up is necessary to prevent damage to the joint. In the long term, remaining bone stock may be adequate for total joint replacement.

Can we do it faster? accelerated rehabilitation following thumb ulnar collateral ligament repair with suture tape augmentation.

Ulnar Collateral Ligament (UCL) injuries are the most common thumb metacarpophalangeal joint ligamentinjury. Rehabilitation protocols traditionally permit return to sport at 12 weeks post-surgery. In this article, we propose anacellerated rehabilitation protocol permitting return to sport at 5-6 post-surgery in the recreational athlete.

Improving Metacarpophalangeal Joint Instability by Joint Implantation in Parallel From a Supernumerary Thumb in Severely Hypoplastic Duplicated Thumbs.

ABSTRACT: Here, we present 2 cases of a severely hypoplastic duplicated thumb classified as Wassel types 5 and 6 and discuss whole-joint implantation from a supernumerary thumb as an alternative to stabilize the hypoplastic metacarpophalangeal (MCP) joint. The aim of the surgical treatment of thumb polydactyly is to reconstruct a functional and aesthetically pleasing thumb. Hypoplasia of joint components and abnormal tendon alignment lead to unpleasing results with angular deformity of the reconstructed thumb. In 2 cases, the MCP joint of the dominant digit was hypoplastic and unstable in all directions. The main problem was underdevelopment of the affected MCP joint, and it was reasonable to attempt to stabilize the unstable joint by adding another redundant joint in parallel. Whole-joint implantation with a flap on a vascular pedicle is useful to repair both joint instability and soft tissue hypoplasia, as in case 1. The vascularized joint can maintain balanced growth potential. However, nonvascularized interphalangeal (IP) joint implantation is a simple solution for repairing MCP joint instability, as in case 2. These joints have no tendon insertions, so we believe they are acting as a splint supporting the hypoplastic joint for a long period. The transfer of composite tissues from the foot has been reported for reconstruction of finger and thumb hypoplasia. Duplicated thumb operation is usually recommended at 1 year old. Similarly, nonvascularized joint implantation in parallel may be a promising choice to overcome MCP joint instability and to maintain range of motion in hypoplastic cases with a duplicated thumb.In conclusion, joint implantation in parallel from a supernumerary thumb could prevent angular deformity and is an alternative to overcome MCP joint instability in cases of a severely hypoplastic duplicated thumb without any donor morbidity.

Reconstruction of the Thumb Metacarpophalangeal Ulnar Collateral Ligament With an Adductor Pollicis Slip: An Anatomic Evaluation.

PURPOSE: Reconstruction of the ulnar collateral ligament (UCL) of the thumb metacarpophalangeal joint is commonly performed for chronic injuries. This study evaluates the anatomic feasibility of using a part of the adductor pollicis tendon to reconstruct UCL. METHODS: Ten cadaveric arms were dissected to evaluate the relationship between the insertions of UCL and the adductor pollicis. A slip of the adductor pollicis was divided from the tendon and transposed dorsally. The dissected tendon was deemed sufficient for reconstruction if it could be reflected to the footprint of the UCL origin. The size of the adductor pollicis slip was then compared with that of UCL. RESULTS: The dissected slip of the adductor pollicis could be fully reflected proximally to the UCL origin in all the specimens, and the insertion was also found to be closely approximated to the UCL insertion, averaging 2 mm distally and 0.6 mm dorsally. CONCLUSIONS: A sufficiently sized partial adductor pollicis tendon can be obtained to reconstruct UCL of the thumb metacarpophalangeal joint, and the location of the adductor pollicis insertion closely approximates that of the UCL insertion. CLINICAL RELEVANCE: The anatomic relationship evaluated in this study relates to a recently described method of the reconstruction of UCL of the thumb metacarpophalangeal joint that does not require free tendon harvest. This study shows that the technique is anatomically feasible.

Arthroscopic mobilization for metacarpophalangeal joint extension contracture.

BACKGROUND: As a first-line surgical treatment for treating metacarpophalangeal (MCP) joint extension contractures, mobilization surgery with open dorsal approach has been indicated. However, this procedure has the possibility to result in postoperative recurrence over the course of time because its invasive open dorsal approach has a negative impact on the postoperative gliding of the extensor mechanism. We report the preliminarily outcomes of patients who underwent a minimally invasive arthroscopic mobilization to alter and enhance their existing surgical strategy in place of MCP joint extension contractures. METHODS: This retrospective study included seven patients with 13 MCP joint extension contractures who had received an arthroscopic release of the bilateral collateral ligament and/or dorsal capsule of affected MCP joint. The extension contractures were caused by long-time immobilization with inadequate extended position of the MCP joint after either hand and wrist fractures, extensor tendon injury, or peripheral nerve palsy. All patients received sufficient exercise under the supervision of a physical therapist for more than 3 months before surgery. However, physical therapy did not improve the MCP joint extension contractures. We measured the active and passive flexion angles preoperatively at 1 and 6 months after surgery. The passive flexion angle was also measured after arthroscopic mobilization on the operation table. Surgery-related complications regarding nerve, vessel, skin, and tendon were also assessed. RESULTS: In all patients, significant improvements were observed in both the active and passive flexion angles 1 month after surgery, and continued to improve 6 months after surgery. Two out of 13 metacarpophalangeal joints developed blisters on the dorsal side of the joint, but conservatively recovered. CONCLUSIONS: Based on the positive improvements observed in our patients, we conclude that this minimally invasive arthroscopic technique has the potential to alter and enhance the surgical treatment strategy for MCP joint extension contractures.

Dynamic Traction Splint as an Alternative Surgical Treatment for Comminuted Intraarticular Fracture of Metacarpophalangeal Joint.

BACKGROUND: Comminuted intraarticular fractures of the metacarpophalangeal joint (MPJ) are difficult to treat. We evaluated the clinical outcomes of using a dynamic traction splint to treat comminuted intraarticular fracture of MPJ. PATIENTS AND METHODS: We conducted a retrospective chart review on patients with comminuted intraarticular fracture of the MPJ treated with a dynamic traction splint at National Cheng Kung University Hospital between March 2014 and February 2018. The surgical procedures consisted of a transverse Kirschner wire insertion and treatment for concomitant injuries. The patients then received staged regular rehabilitation programs under a hand therapists' supervision for 14 weeks. Active range of motion (ROM) of injured digits, Visual Analog Scale score for pain, and return-to-work status were recorded to evaluate functional outcomes. RESULTS: A total of 10 patients were included. All were male patients and aged 8 to 66 years. The most common injury mechanism was motor vehicle accident (70%). The locations of fractures were 1 at the metacarpal head and 9 at the proximal phalangeal bases. Half of the fractures were open. Concomitant injuries were 1 digital nerve severance, 1 extensor tendon rupture, and 3 dorsal skin avulsions. There were no postoperative complications. The active ROM of the MPJ ranged from 40° to 90° with a median ROM of 80°. The Visual Analog Scale score for pain was 0 in 8 patients and 1 in the other 2 patients. All patients returned to their original workplace after rehabilitation. CONCLUSIONS: Dynamic traction splints and postoperative rehabilitation programs could be an alternative treatment for comminuted intraarticular fracture of the MPJ.

Risk Factors Contributing to Early Implant Fracture in Silicone Metacarpophalangeal Joint Arthroplasty for Patients With Rheumatoid Arthritis.

PURPOSE: To identify the risk factors associated with early implant fracture of silicone metacarpophalangeal (MCP) joint arthroplasty using the volar hinge silicone implant for patients with rheumatoid arthritis. METHODS: We retrospectively reviewed 113 fingers of 31 hands that underwent MCP joint arthroplasty between 2008 and 2014, with a minimum follow-up of 3 years,. An implant fracture within 3 years after surgery was regarded as an early implant fracture. Patient records were reviewed for potential risk factors of age, affected fingers, ulnar drift angle, and range of motion of the MCP joint before surgery and 1 year after surgery. Candidate risk factors were compared at the level of the digit and at the patient level. RESULTS: With fracture of the implants as the end point, Kaplan-Meier estimated survival rate was 74.3% at 3 years and 67.9% at 5 years. Early implant fracture was detected in 29 fingers. Bivariate analyses showed significant associations between early implant fracture and MCP joint arc of motion before surgery, MCP joint flexion range 1 year after surgery, and MCP joint arc of motion 1 year after surgery. Multiple logistic regression analysis showed that increased MCP joint flexion range 1 year after surgery was an independent risk factor for early implant fracture. CONCLUSIONS: Increasing MCP joint flexion range was associated with increased fractures of the implants. We propose that the MCP joint flexion range should be restricted to less than 60° in postoperative rehabilitation; it is necessary to educate the patient to permanently avoid excessive flexion of the MCP joint. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Clinical results of the BoneWelding®Fiji® anchor for the treatment of Stener lesions of the thumb.

INTRODUCTION: A new technology (Sportwelding®) was recently presented, which uses ultrasonic energy to meld a resorbable suture anchor at the interface with the host bone. A standardized clinical use was not investigated yet. This study prospectively evaluated the surgical and clinical outcomes of the Fiji Anchor® (Sportwelding®, Schlieren, Switzerland) in the repair of an ulnar collateral ligament lesion of the metacarpophalangeal joint of the thumb. MATERIAL AND METHODS: The range of motion, grip and pinch strength, disability of arm, shoulder and the hand (DASH) and patient rated evaluation (PRWE) score, pain, satisfaction, complications and adverse events were assessed in 24 patients after surgical treatment for an acute displaced rupture or avulsion of the ulnar collateral metacarpophalangeal ligament of the thumb using the Fiji Anchor® after 6, 12 and 52 weeks. RESULTS: At final follow up, the range of motion of the metacarpophalangeal joint reached almost the contralateral side (49.3° SD 11.7°). Thumb opposition showed a Kapandji score of 9.7 (SD 0.5; range 9-10). Grip strength, the lateral, tip and the three jaw pinch showed nearly similar values compared to the contralateral side (83-101%). Pain was low (0.2 SD 0.7 at rest and 0.6 SD 1.0 during load). The DASH score was 5.0 (SD 7.3) and the PRWE score was 4.1 (SD 9.0). 81% of patients were very satisfied at final follow-up. Two patients were rated unstable during the follow-up period due to a second traumatic event. Three cases experienced difficulties during anchor insertion, whereby incorrect anchor insertion resulted in damage to the suture material; however, this was resolved after additional training. CONCLUSION: One advantage of this anchor appears to be its stable fixation in cancellous bone. The surgical treatment of an ulnar collateral ligament lesion of the thumb using the Fiji Anchor® can lead to an excellent clinical outcome with a minor complication rate; however, long-term dangers and the cost effectiveness of the procedure are not known yet.