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.

Lambda Repair: A Novel Repair Technique for Chronic Boutonnière Deformity.

SUMMARY: Correction of a boutonnière deformity is one of the most demanding challenges in hand surgery. Surgical interventions are usually considered when functional use of the finger cannot be obtained after intense hand therapy. The authors introduce their newly described lambda (λ) repair, which is an easy-to-learn, straightforward surgical technique. The method involves an end-to-side tenorrhaphy of the lateral bands, resembling the Greek λ. Patients who underwent a lambda repair were retrospectively evaluated with preoperative and postoperative measurements of proximal interphalangeal (PIP) joint movement. Four patients (two male, two female; median age, 35.5 years) with a median follow-up period of 9.1 months were included. Three patients underwent lambda repairs for isolated boutonnière deformities, and one patient received a vascularized free toe transfer combined with a lambda repair. The preoperative average PIP joint extension lag or deficit was 28.75 degrees and could be reduced to 15 degrees. Preoperative average PIP joint active flexion was 60 degrees, which was improved to 88.75 degrees. No complications were observed. The lambda repair is a new tool in the reconstruction of boutonnière deformity, further expanding the armamentarium of hand surgeons.

Modification of the Zancolli Lasso Procedure for Simultaneous Correction of Wartenberg's Sign.

Ulnar nerve injury initiates an imbalance between the intrinsic muscles and extrinsic extensors of the ring and small fingers, which leads to the characteristic hyperextension of the metacarpophalangeal (MP) joints and flexion of the proximal interphalangeal joints of these 2 digits-commonly referred to as the ulnar claw hand. In addition to these changes in the static posture of the hand, ulnar nerve palsy severely impairs grasp due to deficient active MP joint flexion. In most cases, motor balance can be restored by preventing MP joint hyperextension and augmenting MP joint flexion using the Zancolli lasso procedure (ZLP). Ulnar neuropathy can cause a second motor imbalance between the ulnar intrinsics and the extensor digit minimi leading to an abduction deformity of the small finger known as Wartenberg's sign. The inability to adduct the small finger can be a great source of frustration to patients. Using a cadaveric biomechanical model, we have developed a simple modification of the Zancolli lasso procedure that simultaneously corrects claw deformity and Wartenberg's sign and we report its efficacy in 2 clinical cases.

Quick and safe: why a k-wire-extension-block-fixation of a bony mallet finger is the favoured treatment.

INTRODUCTION: Mallet fingers are the most common tendon injuries of the hand. Bony avulsion distal finger extensor tendon ruptures causing a mallet finger require special attention and management. In this monocentral study, we analyzed the clinical and individual outcomes succeeding minimal invasive k-wire extension block treatment of bony mallet fingers. MATERIALS AND METHODS: In a retrospective study, we sent a self-designed template and a QUICK-DASH score questionnaire to all patients, who were treated because of a bony mallet finger between 2009 and 2022 and fulfilled the inclusion criteria. A total of 244 requests were sent out. 72 (29.5%) patients participated in the study. Forty-five men and twenty-seven women were included. RESULTS: 98.7% (n = 75) of the cases were successfully treated. Patients were highly satisfied with the treatment (median 8.0; SD ± 2.9; range 1.0-10.0). Based on the QUICK-DASH score, all patients showed no difficulties in daily life. The extent of avulsion did not influence the outcome. CONCLUSION: We conclude that the minimally invasive treatment of a bony mallet finger should be offered to every patient, because it is safe, fast, and reliable. Thus, we propose to perform extension-block pinning independently of the articular area.

Direct fixation of fracture fragment with modified double Kirschner wires for the treatment of old bony mallet finger.

BACKGROUND: The management of old bony mallet fingers is complicated. The purpose of this study was to describe direct fixation of fracture fragment with modified double Kirschner wires (K-wires) for treatment of old bony mallet finger, and to evaluate the functional outcomes during long-term follow-up. METHODS: Forty-nine patients with old bony mallet finger were enrolled and underwent surgical treatment from August 2014 to January 2021 in our hospital. Patients were divided into two groups according to whether they had undergone triple K-wires fixation or modified double K-wires with a dorsal brace fixation. The operation time, mean number of intraoperative fluoroscopy, bone union time, functional recovery and incidence of complications were monitored. RESULTS: Neither QuickDASH nor visual analogue scale measurement found statistically significant difference between the two groups (P > 0.05). However, the patients that underwent fixation with double K-wires and a dorsal brace required a shorter operation time and fewer intraoperative fluoroscopy, and exhibited a significantly greater mean final active range of the distal interphalangeal joint flexion, compared to those treated with triple K-wires (P < 0.01). CONCLUSION: Direct fixation of fracture fragment with modified double K-wires was an easy and feasible procedure which could achieve anatomical reduction and stable fixation of the dorsal fracture block of old bony mallet finger with relatively few complications.

Flexor Digitorum Superficialis Excision for Trigger Finger - A Systematic Literature Review.

Background: Division of one or more slips of the flexor digitorum superficialis (FDS) tendon has been posited as an effective surgical modality for advanced or recurrent trigger finger. This may be an effective approach among patients with diabetes or rheumatoid arthritis, or in those with fixed flexion deformities who have poor outcomes from A1 pulley release alone. However, there is limited evidence regarding the effectiveness of this procedure. The role of this study was to systematically review the evidence on functional outcomes and safety of partial or complete FDS resection in the management of trigger finger. Methods: A systematic review was performed according to PRISMA guidelines. PubMed, Cochrane CENTRAL and Ovid Medline databases were electronically queried from their inception until February 2022. English language papers were included if they reported original data on postoperative outcomes and complications following resection of one or more slips of FDS for adult trigger finger. Results: Seven articles were eligible for inclusion, encompassing 420 fingers in 290 patients. All included studies were retrospective. Isolated ulnar slip FDS resection was the most described surgery. Mean postoperative fixed flexion deformity at the proximal interphalangeal joint was 6.0° compared to 31.5° preoperatively, and the proportion of patients with fixed flexion deformity reduced by 58%. Mean postoperative total active motion was 228.7°. Recurrence was seen in 4.7% of digits, and complications occurred in 11.2% of cases. No post-surgical ulnar drift or swan neck deformities were observed. Conclusions: FDS resection for long-standing trigger finger, or in diabetic or rheumatoid populations, is an effective and safe technique with low rates of recurrence. Prospective and comparative studies of this technique would be beneficial. Level of Evidence: Level III (Therapeutic).

Posttraumatic Osteoarthritis of the Distal Interphalangeal Joint: A Follow-Up Study of 12 Years After Nonsurgical Treatment of Mallet Finger Fractures.

PURPOSE: In treatment of mallet finger fractures (MFFs), the aim is to minimize residual extension lag, reduce subluxation, and restore congruency of the distal interphalangeal (DIP) joint. Failure to do so may increase the risk of secondary osteoarthritis (OA). However, long-term follow-up studies focusing on OA of the DIP joint after an MFF are scarce. The purpose of this study was to assess OA, functional outcomes, and patient-reported outcome measures (PROMs) after an MFF. METHODS: A cohort study was performed with 52 patients who sustained an MFF at a mean of 12.1 years (range, 9.9-15.5 years) previously and who were treated nonsurgically. A healthy contralateral DIP joint was used as the control. Outcomes were radiographic OA, using the Kellgren and Lawrence and Osteoarthritis Research Society International classifications, range of motion, pinch strength, and PROMs (Patient-Rated Wrist Hand Evaluation, Quick Disabilities of the Arm, Shoulder, and Hand, Michigan Hand Outcome Questionnaire, 12-item Short Form Health Survey). Radiographic OA was correlated with PROMs and functional outcomes. RESULTS: At follow-up, there was an increase in OA in 41% to 44% of the MFFs. Of all the MFFs, 23% to 25% showed a higher degree of OA than the healthy control DIP joint. Range of motion (mean difference ranging from -6° to -14°) and Michigan Hand Outcome Questionnaire score (median difference, -1.3) were decreased after MFFs but not to a clinically relevant extent. Radiographic OA was weakly to moderately correlated with functional outcomes and PROMs. CONCLUSIONS: Radiological OA after an MFF is similar to the natural degenerative process in the DIP joint and is accompanied by a decrease in range of motion of the DIP joint, which does not clinically affect PROMs. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

The relative motion concept in acute and chronic boutonniere deformity: Invited commentary.

STUDY DESIGN: Retrospective. INTRODUCTION: Boutonniere deformity (BD) is a troublesome injury occurring from rupture of tissue connecting the extrinsic to intrinsic tendon systems. This causes loss of interphalangeal joint balance, and immobilization often results in adherence and difficulty restoring balance. PURPOSES: Review of relative motion flexion (RMF) orthotic use for safe healing during functional activity in 23 patients, and explanation of the rationale. METHODS: Anatomic rationale and clinical experience is reviewed in 8 acute BD patients utilizing RMF orthoses for 6 weeks, and for chronic BD patients, 3 months after serial casting. RESULTS: All patients met the Strickland and Steichen criteria for "excellent" results following treatment, with an average of 35° increase in ROM. DISCUSSION: The anatomic rationale for relative motion recognizes that altering relative positioning between adjacent metacarpophalangeal (MCP) joints produces a protective favorable impact on interphalangeal forces during hand function using 15°-20° greater MCP joint flexion. This provides dorsal and volar protective benefits because the extensor digitorum communis (EDC), a single-muscle-four-tendon system, attaches to the intrinsic lateral band (LB) tendons. With greater MCP flexion, dorsal EDC force is increased, pulling lateral bands medially, while on the volar surface the downward pull of the lumbrical on LB is relaxed due to origin from the flexor digitorum profundus tendon of the injured digit, also a single-muscle-four-tendon system. The RMF orthosis permits protected active motion during functional activity with acute BD. In patients with chronic BD and adequate passive extension, an RMF orthosis for 3 months also produced encouraging results. CONCLUSION: Management of acute BD with RMF orthoses provided earlier recovery of motion and hand function. Similar results occurred for chronic BD using serial casting for adequate extension followed by 3 months of RMF orthotic use and should be attempted prior to surgical intervention, with surgery remaining an alternative.

An in-depth look at zone III and IV anatomy of the finger extensor mechanism and some clinical implications for use of the relative motion flexion orthosis.

BACKGROUND: For hand therapists and hand surgeons acute and chronic injuries of the extensor mechanism (EM) in zones III-IV are challenging to treat with satisfying results. INTRODUCTION: Early active motion combined with relative motion flexion (RMF) orthoses to manage EM zone III injuries and boutonnière deformity has renewed interest in the complex anatomy and biomechanics of the EM. PURPOSE: To provide an in-depth discussion of EM zones III-IV anatomy with emphasis on inter-tendinous structures, often omitted in simplified, model-wise illustrations which focus mostly on the tendinous structures. METHOD: In collaboration the authors combined on the one hand extensive clinical experience and knowledge of the EM literature and on the other hand decades of anatomical, biomechanical and kinesiology research of the EM with special interest for the spiral fibers, through gross anatomy and microdissection anatomy laboratory work, MRI and ultrasonography studies. RESULTS: The inter-tendinous tissues (i.e., spiral fibers) in zone III are of imminent importance for proper functioning of the EM and to prevent boutonnière deformity to develop after EM surgery or injury. DISCUSSION: Inter-tendinous links between the tendinous structures of the EM are necessary for balanced finger motion. The spiral fibers are described in more detail because of their role in controlling volar migration of the conjoined lateral bands and because their disruption makes development of boutonnière deformity more likely. Understanding the anatomy and biomechanics of the EM may assist in progress toward 'proof of concept' for use of RMF orthoses and controlled early active motion after EM injury or surgery. CONCLUSION: Hand surgery and hand therapy practice interventions, including use of RMF orthoses for management of non-surgical and surgical EM injuries may benefit from an in-depth look at the EM zone III and IV anatomy and biomechanics.

Comparative outcomes between surgical treatment and orthosis splint for mallet finger: a systematic review and meta-analysis.

Mallet finger is a commonly encountered condition in daily practice. However, there is currently no consensus on whether surgical intervention or conservative treatment with orthosis splint is superior. In this systematic review and meta-analysis, we compare the treatment outcomes between surgery and orthosis for bony and tendinous mallet finger. We searched PubMed, Embase, and the Cochrane Library according to the PRISMA guidelines from inception to January 15, 2021. The primary outcome was distal interphalangeal (DIP) joint extension lag angle, and secondary outcomes were DIP joint flexion and range of motion (ROM) angle. A total of 297 studies were initially identified, of which 13 (ten retrospective non-randomized controlled studies (non-RCTs) and three RCTs) were included in the final analysis. The results of this systematic review and meta-analysis showed that there was no high level of evidence supporting the superiority of surgery over orthosis in the treatment of mallet finger. Based on the available evidence, surgical intervention and conservative treatment with splint may offer similar clinical outcomes in both bony and tendinous mallet finger.

Boutonniere Versus Pseudoboutonniere Deformities: Pathoanatomy, Diagnosis, and Treatment.

Finger injuries involving the proximal interphalangeal (PIP) joint are common, particularly among athletes. Injury severity is often underappreciated at initial presentation and may be dismissed broadly as a "jammed finger" injury. Delayed diagnosis and treatment of certain injuries can have an important impact on the patient's chance of regaining full function. Central slip and PIP volar plate injuries are frequently encountered injuries that, if left untreated, can lead to the permanent loss of function of the proximal interphalangeal joint. Despite the differing mechanisms of these 2 pathologies, volar plate hyperextension injuries often present with a PIP joint flexion contracture and mild distal interphalangeal joint hyperextension deformity. This is similar to a boutonniere deformity seen after an injury to the central slip, and thus, has been referred to as a "pseudo-boutonnière" deformity. Distinguishing these 2 diagnoses is important, as treatment differs, and highlights the importance of thoroughly understanding the anatomy and relevant clinical applications when evaluating PIP joint injuries.

Prospective Randomized Clinical Trial Comparing 3-Point Prefabricated Orthosis and Elastic Tape Versus Cast Immobilization for the Nonsurgical Management of Mallet Finger.

PURPOSE: The purpose of this randomized trial was to compare the outcomes of using a 3-point prefabricated orthosis with elastic tape versus cast immobilization for the management of nonsurgical mallet finger. METHODS: This study was conducted in a single center. Individuals with a mallet injury requiring nonsurgical management were randomized to 6 weeks of full-time immobilization with either a 3-point prefabricated orthosis and elastic tape or a cast for distal interphalangeal joint extension. Outcomes were assessed at 12 weeks after the initiation of full-time immobilization and 6 months after injury. RESULTS: A total of 70 individuals agreed to participate in the study between April 2017 and April 2021. No statistically or clinically significant differences were found between the groups regarding distal interphalangeal joint extension lag, distal interphalangeal joint flexion deficits, function according to the brief Michigan Hand Outcome Questionnaire, and pain on the Numeric Pain Rating Scale. The overall findings for both treatment groups included means of <15° of extensor lag and minimal pain (mean, <1.2 of 10) at the 6-month outcome assessment. CONCLUSIONS: The use of a 3-point prefabricated orthosis with elastic tape and cast are both appropriate immobilization options for the management of nonsurgical mallet finger. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

Effect of a Flexor Digitorum Superficialis Hemitenodesis on Reducing Volar Plate Strains for Swan Neck Deformities.

BACKGROUND: Flexor digitorum superficialis (FDS) hemitenodesis is a common procedure to treat swan neck deformity (SND). We hypothesize that this surgical technique is a biomechanically effective way to reduce strain in the volar plate at the proximal interphalangeal joint (PIPJ). METHODS: Fifteen digits from 5 cadaveric specimens were tested using a novel in vitro active finger motion simulator under 4 finger conditions: intact, SND, FDS hemitenodesis, and FDS hemitenodesis with distal interphalangeal (DIP) joint fusion. Tensile loads in FDS and flexor digitorum profundus (FDP) and joint ranges of motion were measured by electromagnetic tracking. In addition, strain gauges were inserted under the volar plate to measure strain during PIPJ hyperextension. Results were analyzed using 1-way repeated-measures analysis of variance tests. RESULTS: The SND condition increased volar plate strain by 176% ± 25% (P < .001) compared with the intact condition. The FDS hemitenodesis repair relieved more than 50% of the SND strain, restoring it to within no statistical difference from intact. The DIP fusion further reduced strain with no further statistical significance. At full flexion, FDS and FDP tendon loads diverged as a function of the test condition (P < .001). With the FDS hemitenodesis, the FDP load increased by 2.1 ± 1.5 N from the SND condition (P < .001), whereas the FDS load decreased by 1.3 ± 1.3 N (P = .012). CONCLUSION: The FDS hemitenodesis repair restored strains to within 3.0 milli-strain of the intact condition with no significant difference. Application of DIP fusion did not further protect the PIPJ from increased hyperextension and further exacerbated the imbalance of flexor tendon loads.

Management of chronic mallet finger: Indications and long-term results of Fowler central slip tenotomy and distal interphalangeal joint arthrodesis.

INTRODUCTION: Many surgical techniques have been described to correct the sequelae of chronic mallet fingers (MF), but no clear therapeutic strategy has been defined. We have reported the choice of their management according to the severity of the deformities. Two procedures were compared: Fowler's central slip tenotomy (CST) and arthrodesis of the distal interphalangeal joint (DIP). HYPOTHESIS: The use of our decision tree, based on the severity of deformity (flexion deformity at the DIP and recurvatum at the proximal interphalangeal joint), allows good long-term clinical results to be obtained. MATERIAL AND METHODS: Thirty-three patients (34 fingers) were operated on for sequelae of chronic MF either by CST or by DIP arthrodesis. Patients with ≤35° DIP flexion deformity and <25° proximal interphalangeal (PIP) recurvatum, without DIP joint involvement (osteoarthritis, subluxation, stiffness), were treated with CST. For the others, arthrodesis of the DIP joint was performed. RESULTS: Thirteen patients (13 fingers) were evaluated in the CST group with a mean follow-up of 13 years. There were no postoperative complications and no failures. The mean DIP residual extension lag was 4.23° with complete correction of the PIP recurvatum. All patients would redo the intervention in hindsight. The improvement in Quick-DASH was statistically significant (p=0.01). Twenty patients (21 fingers) were included in the DIP arthrodesis group with a mean follow-up of 10 years. Two failures (9.5%) occurred due to failed correction of the PIP recurvatum. No worsening of the deformities was reported, and they were corrected in 90% of cases. The absence of correction of the PIP recurvatum was more frequent in MF bone (p=0.01). All except 1 (95%) patient, who reported a lack of mobility of the DIP joint, would repeat the procedure. Quick-DASH was improved for all patients. DISCUSSION: CST is effective in correcting deformities in chronic MFs for ≤35° DIP flexion deformity and <25° PIP recurvatum without DIP joint involvement. In other cases, it is preferable to perform a DIP arthrodesis by combining, if necessary, a complementary procedure to correct the PIP recurvatum. LEVEL OF EVIDENCE: IV, retrospective study.

Acute Mallet Finger Injuries-A Review.

Acute disruptions of the terminal extensor tendon are common and can result in significant dysfunction if not recognized and treated appropriately. This article provides a topical review of the contemporary literature concerning acute mallet finger injuries. It also proposes a modification to the Doyle classification to make it more encompassing and less prone to interobserver error.