Advancing glenohumeral dysplasia treatment in brachial plexus birth injury: the end-to-side spinal accessory to suprascapular nerve transfer technique.

PURPOSE: Brachial plexus birth injury (BPBI) is a common injury with the spectrum of disease prognosis ranging from spontaneous recovery to lifelong debilitating disability. A common sequela of BPBI is glenohumeral dysplasia (GHD) which, if not addressed early on, can lead to shoulder dysfunction as the child matures. However, there are no clear criteria for when to employ various surgical procedures for the correction of GHD. METHODS: We describe our approach to correcting GDH in infants with BPBIs using a reverse end-to-side (ETS) transfer from the spinal accessory to the suprascapular nerve. This technique is employed in infants that present with GHD with poor external rotation (ER) function who would not necessitate a complete end-to-end transfer and are still too young for a tendon transfer. In this study, we present our outcomes in seven patients. RESULTS: At presentation, all patients had persistent weakness of the upper trunk and functional limitations of the shoulder. Point-of-care ultrasounds confirmed GHD in each case. Five patients were male, and two patients were female, with a mean age of 3.3 months age (4 days-7 months) at presentation. Surgery was performed on average at 5.8 months of age (3-8.6 months). All seven patients treated with a reverse ETS approach had full recovery of ER according to active movement scores at the latest follow-up. Additionally, ultrasounds at the latest follow-up showed a complete resolution of GHD. CONCLUSION: In infants with BPBI and evidence of GHD with poor ER, end-to-end nerve transfers, which initially downgrade function, or tendon transfers, that are not age-appropriate for the patient, are not recommended. Instead, we report seven successful cases of infants who underwent ETS spinal accessory to suprascapular nerve transfer for the treatment of GHD following BPBI.

Biomechanical Comparison of 3 Thumb Ulnar Collateral Ligament Repair Methods.

PURPOSE: Differences in range of motion, pinch strength, biomechanical strength, or joint angulation have previously been investigated for various means of treatment of ulnar collateral ligament (UCL) tears. We sought to address a gap in the literature by comparing thumb metacarpophalangeal (MCP) joint angle measurements and biomechanical strength before complete, acute UCL tear and after repair with suture anchors (SA), suture tape (ST) anchor augmentation, or reconstruction with palmaris longus graft (PL). METHODS: Thumbs and, if present, the PL tendon were harvested from 15 fresh-frozen cadavers. Each thumb specimen was secured into a servohydraulic biomechanical testing frame to evaluate native radiographic MCP joint angles at 0° flexion when loaded with 0, 5, and 13 N of radial force. Subsequently, a single hand surgeon (S.M.K.) performed complete transection and UCL repair via 1 of 3 methods: SA (n = 5), ST (n = 5), or reconstruction with PL (n = 5). Following repair, MCP joint angles were radiographically evaluated. Specimens that did not fail during joint angle testing were transferred to a separate testing frame for load-to-failure testing. Angle measurements and mean load-to-failure were compared between the groups, and angulation was also compared with each group's native control. RESULTS: Both ST and SA groups demonstrated comparable stiffness to their native controls, whereas the PL group was significantly more lax. The ST repair was significantly stiffer than the other constructs. ST also required higher forces to reach failure compared to both SA and PL. No difference was found between SA and PL groups. CONCLUSIONS: Although both ST and SA constructs recapitulate native joint stiffness, repair with ST demonstrated the greatest biomechanical strength in stiffness and load-to-failure. CLINICAL RELEVANCE: For complete, acute tears of the thumb UCL, ST may be superior for maintaining MCP joint stability and strength over SA and PL.

The medial forearm fascia and lateral forearm fascia contribute to overhead elbow extension in displaced olecranon fractures: a biomechanical study.

BACKGROUND: In nonoperative management of displaced olecranon fractures, patients are able to maintain overhead extension despite a persistent nonunion. It has been hypothesized that this is feasible because of an intact lateral cubital retinaculum. The purpose of this biomechanical study was to determine the contribution of the medial and lateral cubital retinacula to overhead extension in the setting of a displaced olecranon fracture. METHODS: Eight fresh-frozen cadaveric upper-extremity specimens were used in this study. The triceps muscle was loaded through a pulley system operated by an Instron 8874 Biaxial Servohydraulic Fatigue Testing System at a rate of 10 mm/second to simulate overhead elbow extension. Each specimen was tested in 4 states: (1) native state with an intact olecranon; (2) transverse olecranon fracture; (3) transection of 1 cubital retinaculum (medial or lateral); and (4) transection of both medial and lateral cubital retinacula. The primary outcome was the ability to perform overhead extension. The secondary outcome was the force needed to generate extension. RESULTS: Elbow extension was noted in each specimen for trials 1, 2, and 3. Only when both the lateral fascia and medial fascia were transected was elbow extension not achieved. There was no significant difference in the force required to generate extension in the first 3 trials (P = .99). There was no significant difference in the change in the maximum force required to achieve extension between the specimens with only the medial side transected and the specimens with only the lateral side transected (P = .07). DISCUSSION: In the setting of an olecranon fracture, this biomechanical study suggests that if either the lateral or medial cubital retinaculum remains in continuity with the distal ulna, active overhead extension can be maintained. This finding may explain the positive clinical outcomes of nonoperative management of displaced olecranon fractures in the elderly patient population. Determining the integrity of the fascial structures preoperatively may help select candidates for nonoperative treatment of displaced olecranon fractures.

A bibliometric analysis of the 50 most influential publications on distal biceps repair.

PURPOSE: The purpose of this bibliometric study was to identify and analyze the most cited publications on acute distal biceps repair. METHODS: Using the Clarivate Analytics Web of Science database, we searched for the top 50 most cited publications on acute distal biceps repair and analyzed them based on various metrics. RESULTS: The top 50 publications were cited a total of 3171 times and approximately 151 times per year. However, although the literature on the topic is quite extensive, most publications only contain low-level evidence. In fact, 74% of the 50 most cited publications on the topic contain either level IV or V evidence. CONCLUSION: This study, through bibliometric analysis, demonstrates that the most often cited studies about acute distal biceps tendon repair are low level of evidence designs. This common injury and study design are ripe for larger randomized or prospective cohort studies.

The top 50 most cited articles on olecranon fractures: a bibliometric analysis.

PURPOSE: Citation analysis has been used to determine the impact of an article in a medical specialty. The purpose of this study was to identify the 50 most cited articles on olecranon fracture outcomes, indications, techniques, procedural descriptions, and complications and analyse their characteristics. METHODS: The Web of Science database was used to search for publications related to olecranon fractures. The top 50 most cited articles that met the inclusion criteria were recorded and reviewed in terms of journal and year of publication, country of origin, type of study, and level of evidence. RESULTS: The top 50 articles were cited a total of 2165 times and the year of publication ranged from 1957 to 2014. Of the 50 articles identified, 43 were case series correlating with a Level IV evidence designation. The top 50 articles were published in 20 different medical journals and originated from 18 different countries. CONCLUSION: The majority of the articles analysed were uncontrolled case series that reported outcomes and complications surrounding the operative treatment of olecranon fractures. The top 50 most influential articles pertaining to olecranon fractures provides physicians and residency programs with a high-yield list of publications to reference on the topic.

The top 50 most cited articles in both-bone forearm open reduction internal fixation in the skeletally mature patient.

PURPOSE: Both-bone forearm fractures in the adult population frequently and usually necessitate an operative reduction. The purpose of this study was to identify the 50 most cited publications regarding both-bone ORIF and evaluates their level of evidence to help guide the best treatment and management practices, as well as gauge the current level of inquiry into this topic. METHODS: The Clarivate Analytics Web of Knowledge Database was queried. The top 50 most cited articles identified as relevant were analyzed. Aggregate citation counts, citation density, type of study, and level of evidence were documented for each of the 50 articles. Abstracts from the last decade of prominent orthopaedic meetings were analyzed to determine the current level of inquiry into this area. RESULTS: The initial search yielded 408 results. There were 27 articles published before 2000 and 23 after. The total summation of citations for the top 50 articles totaled 2062. Each study was classified according to its study design and level of evidence. The most common was case series (34). Level IV studies were most numerous (34). Since 2010, the subject of both-bone forearm fracture ORIF was presented 8 times at prominent orthopaedic conferences. CONCLUSION: Our work demonstrated 54% of top-50 studies are pre-2000 and the majority are Level IV evidence. Additionally, despite the established treatment, there is active inquiry into this topic. Higher quality research can be helpful to validify treatment and management options.

Trends and epidemiology of radial head subluxation in the United States from 2004 to 2018.

BACKGROUND: Increased body mass may predispose children to a greater risk for radial head subluxation (RHS). Recent studies in the literature have reported a plateau in obesity prevalence among infants and toddlers. This study sought to examine recent epidemiological trends in RHS incidence from 2004 to 2018 using the National Electronic Injury Surveillance System database to determine how obesity patterns may affect RHS incidence. METHODS: The National Electronic Injury Surveillance System (NEISS) database was queried for patients 6 years of age or younger presenting with radial head subluxation between January 1, 2004 and December 31, 2018. Patient demographics, mechanisms of injury, and location of injury were recorded. RESULTS: An estimated total 253,578 children 6 years or younger were treated for RHS with 14,204 (95% CI = 8124-20,284) in 2004 to 21,408 (95% CI = 12,882-29,934) in 2018. The overall annual rate of RHS per 10,000 children ≤ 6 years was 6.03 (95% CI = 4.85-7.58). The annual rate of RHS per 10,000 children ≤ 6 years increased (m = 0.200, ß = 0.802, p < 0.001) from 5.18 (95% CI 2.96-7.39) in 2004 to 7.69 (95% CI = 4.63-10.75) in 2018. The most common mechanism associated with RHS was falls (39.4%) with 103,466 (95% CI 74,806-132,125) cases. Pulls accounted for the second most common mechanism of injury, accounting for 90,146 (95% CI 68,274-112,018) cases or 36.2%. Yearly RHS incidence was compared to obesity prevalence for ages 2-5 children provided by the National Health and Nutritional Examination Survey (NHANES) surveys. Changes in obesity prevalence may visually reflect RHS incidence trends, but no causality between obesity prevalence and RHS incidence could be confirmed. CONCLUSION: This study corroborated previous findings that falls and arm pulling contribute to the vast majority of RHS cases. The nonsignificant rise in RHS cases may reflect a possible plateau in obesity prevalence of children aged 2-5 years in recent years. LEVEL OF EVIDENCE: III.

WALANT Hand Surgery: Do the AORN Guidelines Apply?

This study evaluates current guidelines for patients receiving local anesthesia, set forth by the Association of Perioperative Nurses (AORN), within the context of hand surgery. The study reviewed 217 patients and 265 operations performed under wide-awake local anesthesia no tourniquet (WALANT) technique in an outpatient procedure room with minor field sterility. Only the surgeon, one resident, and one circulating nurse were present. All surgical complications were documented, including any infection at postoperative follow-ups. One female patient developed a deep surgical site infection (SSI) following repair of her flexor digitorum superficialis and flexor digitorum profundus, which resolved after irrigation/debridement. We report 0% intraprocedural complication, 0% superficial SSI, and 0.37% deep SSI (n = 1) incidence across this cohort. Most institutions require two nurses present for local anesthesia, but our low complication and infection incidence suggest a single circulating nurse present during WALANT hand surgeries may improve nurse staffing, drive greater turnover efficiency, and reduce costs. (Journal of Surgical Orthopaedic Advances 30(3):156-160, 2021).

The 50 most cited papers in chronic scapholunate reconstruction: a bibliometric analysis.

PURPOSE: This study identifies the most impactful papers on scapholunate reconstruction and provides a quantitative assessment of the impact of these papers in order to inform future clinical practice, education, and research of this condition. METHODS: The Scopus database was used in May 2020 to identify the 50 most cited clinical articles pertaining solely to chronic scapholunate reconstruction. Citation number and density, publication variables, and Altmetric Attention Scores (AASs) were collected and analyzed. RESULTS: The top 50 articles on chronic scapholunate reconstruction produced 1,868 total citations, with an average of 37.36 ± 39.90 citations per article (range 7-196) and an average citation density of 2.44 ± 2.27. US-based publications (n = 20) and articles published in Journal of Hand Surgery (n = 24) were associated with significantly higher citation number and density (p < 0.01 - p = 0.018). In addition, sample size was positively correlated with citation density (rho = 0.312, p = 0.029). Fourteen articles were associated with an AAS (mean score = 4.07 ± 4.70). There was no significant association between AAS and citation number or density, but AAS did significantly predict citation density (coefficient = 0.378, 95% CI: [0.013-0.741], p = 0.043). CONCLUSION: Numerous factors, such as journal of publication, location, and sample size, were significantly associated with citation number and/or citation density. Interestingly, AAS was predictive of, but not directly correlated with citation density, suggesting that the impact of scapholunate literature may not be adequately captured with a citation analysis.

Treatment of Traumatic Elbow Instability With an Internal Joint Stabilizer.

PURPOSE: Current options for treating elbow instability include bony and/or ligamentous fixation with orthosis or cast immobilization, transarticular cross-pinning, temporary bridge plating, and hinged or rigid external fixation. Our purpose was to evaluate the recently developed internal joint stabilizer (IJS), which acts as an internal external fixator of the elbow. Our primary end point was to assess whether use of the device results in a stable and congruent reduction of the ulnohumeral and radiocapitellar joints in patients with acute or chronic elbow instability as a result of trauma. In our series, patients with elbow instability as a result of acute or chronic trauma were treated with an IJS. METHODS: This retrospective study reviewed 20 patients who underwent placement of a U.S. Food and Drug Administration (FDA)-approved IJS for elbow instability. Serial physical examinations and radiographs were performed to verify stability. Patients were instructed that, if they are dissatisfied with their postoperative motion, a secondary contracture release operation will be offered to them. Patients were asked to complete outcome-scoring questionnaires including the Disabilities of the Arm, Shoulder, and hand (DASH) and Mayo Elbow Performance (MEP) score. Complications were monitored for all patients. RESULTS: Twenty patients who underwent placement of an IJS for persistent elbow instability were reviewed. Patients with a flexion-extension arc of 70° or less at 12 weeks were offered a staged arthroscopic contracture release. The average MEP score improved from 12.2 ± 12.4 to 82.5 ± 14.3 and the average DASH score improved from 85.3 ± 23.0 to 37.26 ± 29.3. The average postoperative flexion-extension arc at most recent follow-up was 124.3° ± 14.9°, with a median follow-up of 17 months (8 weeks-25 months). CONCLUSIONS: Use of an IJS allows for early, congruent, and stable ulnohumeral and radiocapitellar range of motion in instances of persistent elbow instability. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Brachialis syndrome: a rare consequence of patient positioning causing postoperative median neuropathy.

BACKGROUND: Poor positioning of patients can result in devastating permanent neurologic deficits. We describe a previously unreported cause of median nerve compression that we have termed the brachialis syndrome, associated with patient positioning that results in permanent median nerve damage. METHODS: We identified this condition affecting 6 median nerves. All patients underwent surgical decompression of the proximal median nerve at the level of the antecubital fossa. RESULTS: Five patients presented with symptoms of median nerve compression; 6 affected median nerves manifested brachialis syndrome after a lengthy index surgery. Every patient had a similar presentation characterized by a mixed sensory and motor deficit. Average time to symptom presentation postoperatively was 1 hour. Two patients had delayed time to decompression, one of 25 days and one of 92 days. In the additional patients, the average time to decompression was 19.7 hours. At median nerve decompression, the brachialis was found to have varying degrees of muscle necrosis. In the patients whose decompression was delayed, there was only partial neurologic recovery at follow-up to 1 year. In the patients expeditiously decompressed, full neurologic recovery occurred in 1 to 14 days. CONCLUSIONS: This is the first description of the brachialis syndrome. During surgery, arms were placed into full extension, compressing the brachialis against the trochlea. The brachialis reliably developed necrosis, resulting in swelling, compressing the median nerve against the lacertus fibrosus. Two patients with delayed decompression had poor neurologic outcomes. This supports modification of patient positioning, postoperative vigilance, and timely surgical management of brachialis syndrome.

Outcomes of arthroscopic treatment of osteochondritis dissecans of the capitellum and description of the technique.

HYPOTHESIS: We hypothesize that a technique for all-arthroscopic fixation of capitellum osteochondritis dissecans (OCD) lesions using suture fixation and autogenous iliac crest bone grafting offers a successful alternative to open internal fixation techniques as shown by 2-year validated patient-reported outcomes. METHODS: Our technique uses arthroscopic all-inside suture fixation with iliac crest autogenous bone grafting. The procedure was performed on 4 elite-level, adolescent athletes presenting with 5 unstable capitellum OCD lesions resulting in elbow pain, limited range of motion, and decreased ability to play. Magnetic resonance imaging showed an unstable OCD lesion, which was correlated with arthroscopy. Postoperatively, patients were evaluated by the short version of the Disabilities of the Arm, Shoulder and Hand questionnaire; Oxford Elbow and Mayo Elbow scores; visual analog scale; postoperative range of motion; and return to play. RESULTS: Three female patients and one male patient aged 13 to 15 years underwent the procedure. The mean final follow-up period was 2.8 years. Union was achieved in all patients, as seen on magnetic resonance imaging at a mean of 3 months. At follow-up, the mean loss of extension was 2°. Mean flexion was 153°. There was no loss of supination or pronation. The mean score on the short version of the Disabilities of the Arm, Shoulder and Hand questionnaire was 11. The mean Mayo Elbow score was 88. The mean Oxford Elbow score was 42. The mean visual analog scale score was 2. The mean time to return to play was 4 months. All patients continued to compete at an elite level. There were no infections or cases of fixation failure, and no patients required conversion to open surgery or needed revision surgery. CONCLUSION: Arthroscopic all-inside fixation of unstable OCD lesions is a successful technique, facilitating athletes to return to an elite level of play.

Mapping the Landscape of Brachial Plexus Birth Injury Research: A Comprehensive Bibliometric Study.

Brachial plexus birth injury (BPBI) is a relatively common condition that poses a significant challenge to children who endure functional impairments later on. This comprehensive bibliometric analysis sought to quantitatively evaluate the existing literature on BPBI, shedding light on authorship, collaboration, publication trends, and keyword analysis to both inform the medical community and foster future research growth. A thorough search of the Web of Science database yielded 712 relevant documents published between 1986 and 2022. The analysis utilized Biblioshiny (K-Synth Srl, Naples, Italy) for bibliometric data, alongside VOSviewer (Centre for Science and Technology Studies, Leiden University, The Netherlands) and TextRazor (TextRazor Ltd., London, UK) for keyword categorization. The literature had an average annual growth rate of 7.94%, with an average document age of 12 years. Collaborative efforts demonstrated 9.6% international co-authorship, with the United States prominently leading global collaborations. Top producing authors included Yang, Kozin, and Clarke, while the most cited authors were Clarke, Waters, and Curtis. Journals such as the Journal of Pediatric Orthopedics and Plastic and Reconstructive Surgery emerged as key contributors to the literature. Keyword analysis illuminated prevalent categories like "society" and "health," underscoring the multifaceted nature of BPBI research. The findings from this bibliometric analysis highlight the dynamic and collaborative landscape of BPBI research, emphasizing the pressing need for continued contributions to address existing gaps in knowledge, enhance global collaboration, and advance the understanding and treatment of this complex condition. Beyond quantitative metrics, this study holds particular significance in its role as a compass for researchers, practitioners, and policymakers invested in BPBI. By offering insights into influential authors, institutions, and emerging trends, this analysis serves as a valuable resource, guiding future research endeavors, fostering interdisciplinary collaboration, and ultimately contributing to improved outcomes for individuals affected by BPBI. The importance of this study lies not only in its informative content but also in its potential to catalyze a collective effort toward refining treatment modalities, promoting preventative measures, and enhancing the overall quality of care for those navigating the challenges of BPBI.

Glenohumeral Dysplasia Following Brachial Plexus Birth Injuries: A Review.

BACKGROUND AND OBJECTIVES: Despite the high morbidity associated with glenohumeral dysplasia (GHD) in children with brachial plexus birth injuries, the progression of this condition often remains unnoticed, even after correcting for the underlying brachial plexus birth injuries. GHD, driven by a multifactorial process involving disruptions in both direct and indirect neural regulation of bony and muscular structures, can lead to intermittent or permanent shoulder mobility imbalances, significantly impacting the quality of life of those affected. Recent research efforts are increasingly directed toward identifying the root causes, managing the deformity, and determining effective treatment options for correcting GHD. METHODS: A comprehensive search strategy was used by the authors to identify relevant literature relating to the progression, pathoanatomy, clinical presentation, and management of GHD following brachial plexus birth injuries across various search engines, such as PubMed, Scopus, and Embase. Considering the topic's interdisciplinary nature, articles were retrieved from both neurosurgical and orthopaedic journals to enrich the review. RESULTS: Given the challenges in managing patients with brachial plexus birth injuries, a multidisciplinary care team consisting of certified occupational hand therapists, neurosurgeons, plastic surgeons, and orthopedic surgeons, specializing in brachial plexus injuries should be advocated for. The aim of this collaborative effort is to correct brachial plexus birth injuries and prevent the persistence of GHD. CONCLUSION: As research continues to focus on understanding the complexities of this condition, the aim of this review article is to summarize the current literature on the course of brachial plexus birth injury and the development of GHD. By doing so, we hope to provide neurosurgeons with the necessary knowledge and essential tools needed to identify and effectively treat GHD during management of brachial plexus birth injuries.

Outcomes of glenohumeral dysplasia after brachial plexus birth injury using the Sup-ER orthosis.

We investigated the efficacy of the supination-external rotation ('Sup-ER') orthosis, designed as a non-operative treatment to maintain normal anatomical growth of the shoulder, on the progression of glenohumeral dysplasia in patients with brachial plexus birth injuries. The Sup-ER orthosis was fabricated for 20 infants diagnosed with glenohumeral dysplasia after brachial plexus birth injuries and its success in correcting glenohumeral dysplasia was confirmed by objective calculations of the alpha angle on serial ultrasound findings and improvement in Active Movement Scale scores. Of the 20 patients, 14 had successful resolution of glenohumeral dysplasia, confirmed by shoulder abduction, shoulder flexion, external rotation and supination, Active Movement Scale scores and improving alpha angle measurements. Failure to rectify glenohumeral dysplasia, evidenced by worsening ultrasound findings and Active Movement Scale scores, necessitated a change to operative management in six patients.Level of evidence: IV.

Successful Use of WALANT in Local and Regional Soft Tissue Flaps: A Case Series.

The wide awake local anesthesia no tourniquet (WALANT) technique has been proven to be safe and effective for upper extremity surgery. WALANT does not require extensive medical clearance and allows for intraoperative assessment of range of motion. Additionally, it is frequently associated with lower costs and less postoperative pain when compared with traditional methods of anesthesia. Despite its expanded use for hand procedures, there are sparse data to support the use of WALANT in local and regional soft tissue flaps. Methods: A retrospective review was performed. Twenty-one patients who underwent a local or regional soft tissue flap surgery using the WALANT technique from February 2, 2018 to February 25, 2022 were included in our analysis. Results: Overall, one Louvre flap, two posterior tibial artery perforator propeller flaps, two reverse radial forearm flaps, two Quaba flaps, six cross finger flaps, one reverse homodigital island flap, three first dorsal metacarpal artery flaps, two thenar flaps, and two Moberg flaps were performed. Patients were followed up for an average of 11.9 ± 8.1 weeks. During this time, no postoperative complications occurred. All patients demonstrated appropriate healing at donor and recipient sites. Full range of motion was regained for all patients. Conclusions: WALANT is safe and effective for use in local and regional soft tissue flap surgery. Surgeons should consider this technique for more involved procedures such as flap surgery, as preliminary results demonstrate positive outcomes and potentially superior recovery for patients.

Journal Discipline Plays a Significant Role in Academic Attention But Not in Social Media Attention in the Peripheral Nerve Literature.

Evaluating the impact of articles can be performed through bibliometric analysis or social media impact using the Altmetric Attention Score (AAS). The purpose of this study was to report on the social media impact of peripheral nerve studies; how article demographic factors, such as journal specialty (hand, orthopedics, plastic surgery), affect AAS; and how AAS correlates with bibliometrics, namely citation number. While orthopedic journals received the highest academic attention, there was no significant difference in social media attention between journal groups. These findings suggest AAS may be useful to authors in deciding which journal in which to pursue publication. [Orthopedics. 2023;46(3):e143-e148.].

Proximal Interphalangeal Joint Congruity: A Biomechanical Study.

BACKGROUND: Surgical approaches to the proximal interphalangeal (PIP) joint often require disruption of soft tissue stabilizers. Additionally, PIP joint injuries frequently result in soft tissue disruption. This study evaluates the necessity of repairing soft tissue stabilizers by assessing their role in maintaining native joint congruity. METHODS: Eight specimens were used to evaluate congruity at 0° and 30° flexion when loaded with 2 N of valgus force. This was performed in the native joint and after sequential sectioning of the surrounding ligaments in order: volar plate (VP), radial collateral ligament (CL), and ulnar CL. The skin flap was sutured with the ligaments unrepaired and the load was reapplied. Radiographs were taken after each load and used to measure the joint line convergence angle (JLCA). RESULTS: Mean JLCA increased in both degrees of flexion after ligaments were sectioned but was only significantly different from the native joint after the VP was disrupted along with 1 CL. Joint congruity improved following repair of the skin flap in both degrees of flexion but was not significant. Joints were more congruent in 30° flexion for all subgroups, but none were significantly different compared to 0° flexion. CONCLUSIONS: Disruption of the VP is insufficient to significantly alter PIP joint congruity. While sectioning of both the VP and CLs resulted in a statistically significant change in joint congruity, mean JLCA demonstrated changes of minor clinical significance. The osseous anatomy of the phalanges imparts inherent stability that maintains a congruent joint despite loss of the soft tissue stabilizers.