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.

The mechanics of the collateral ligaments in the metacarpophalangeal joints: A scoping review

BACKGROUND

The metacarpophalangeal (MCP) joint's collateral ligaments have been extensively debated, with no clear consensus on their mechanics. Understanding their function is crucial for comprehending joint movement and stability.

METHODS

A thorough search was conducted across databases, including PubMed, Scopus, Cochrane library and grey literature. A total of 59 articles were identified, and after rigorous evaluation, six articles were included in the review.

RESULTS

The analysis underscores two principal findings. Firstly, the principal and accessory collateral ligaments exhibit consistent tension influenced by the MCP joint's position. This tension varies across different sections of the ligaments. Secondly, the ligaments' interaction with the joint structure plays a pivotal role in defining the range of motion of the joint.

CONCLUSION

Preliminary findings from this review indicate that MCP joint collateral ligament tension varies with joint position. Increased tension in the principal collateral ligament during flexion and isometric behavior of its volar portion in extension are observed. The accessory ligament may tighten during extension. The shape of the metacarpal head appears to influence this tension. These insights, while informative, call for further detailed research to deepen our understanding of MCP joint mechanics.

Outcomes of Thumb Metacarpophalangeal Joint Arthrodesis Using the XMCP Intramedullary Interlocking Device

Purpose

The intramedullary interlocking device for metacarpophalangeal (MCP) joint arthrodesis (XMCP, Extremity Medical, Parsippany, NJ) has been shown to promote union at a precise angle, provide strong fixation without the need for prolonged immobilization, and lower the incidence of hardware irritation and revision surgery. In this study, we evaluated the clinical outcomes of patients undergoing MCP joint arthrodesis with the XMCP system using a retrospective chart review, patient reported outcomes, and radiographic analysis.

Methods

A retrospective chart review and phone survey was conducted on 57 patients (58 cases) from a single institution between 2017 and 2022. The primary outcome was patient satisfaction, including pre- and postoperative Numeric Rating Scale (NRS) pain scores, Disabilities of Arm Shoulder and Hand (QuickDASH) outcomes, perceived grip strength, and willingness to undergo the procedure again. Secondary outcomes included the need for revision procedures, successful fusion of arthrodesis, and postoperative complications.

Results

Of the 57 patients who underwent MCP joint arthrodesis of the thumb using the XMCP fusion device, a total of 43 (75%) completed the phone survey. The average age of patients was 67 years with an average clinical follow-up of 9 months (range 1-65 months). Patients who participated in the phone survey questionnaire had an average QuickDASH score of 24.7 ± 20.5. Average perceived NRS scores were 6.2 ± 3.5 and 1.2 ± 2.1 before and after surgery, respectively. Average perceived grip strength of patients was 3 ± 1.3 out of 5. When evaluating for concurrent procedures, there was no statistically significant difference in pre- or postoperative NRS scores. In total, 38 (88%) patients were satisfied with the procedure, and 39 (91%) patients would undergo the procedure again.

Conclusion

Metacarpophalangeal joint arthrodesis of the thumb with the intramedullary fusion device is reproducible, allows for immediate use without immobilization, has a low number of complications, and provides improved function and pain relief.

Level of Evidence

Therapeutic III.

Innovations in Small Joint Arthroscopy

With advancements in surgical instrumentation and techniques, the role of arthroscopic and arthroscopic-assisted surgical procedures is ever-growing. Arthroscopy offers direct, magnified visualization of pathology and reductions and is more accurate than relying on intraoperative fluoroscopy alone. It also minimizes soft tissue stripping, which is of particular importance to smaller fracture fragments whose vascularity is precarious and can be injured through open approaches.

Simultaneous quadruple dislocations of the hand in a motorcyclist: A case report

Herein we present a case of four simultaneous dislocations of the hand resulting from a motorcycle accident in a young man. In this case, the 1st CMC, MCP, and IP joints of the right hand were dislocated along with right perilunate dislocation. Perilunate dislocation was treated with open reduction and internal fixation. Close reduction of IP and CMC was done and CMC was fixed by pins. MCP dislocation was treated by open reduction and pinning in addition to collateral ligament and capsular repair. In follow-up excellent functional activity and range of motion were observed.

Why is the prevailing model of joint manipulation (still) incorrect?

For manipulation, this paper addresses arguably the most fundamental question that can be asked about any therapeutic intervention: what is it? In answering this question, this paper presents the prevailing model of joint manipulation (of Sandoz) and explains why this influential model is fundamentally flawed. The early research on 'joint cracking' that led to the development of this model is described in chronological order, alongside how this research was misinterpreted, which gave rise to the model's flaw. Of concern, the flaw in this model makes worrying predictions that could lead to dangerous clinical decisions. Understandably, these predictions have attracted criticism over the use of manipulation as a therapeutic intervention. A corrected model, first published by Evans and Breen more than 15 years ago, is then presented and explained. Unlike the flawed model, this corrected model makes predictions in line with all available empirical data and additionally provides reassuring answers to critics. Many current definitions of manipulation have inherited the flaw from Sandoz's model. Hence, a better, empirically derived definition, consistent with the corrected model, is now required.

Evidence for the presence of synovial sheaths surrounding the extensor tendons at the metacarpophalangeal joints: a microscopy study

MRI-detected inflammation around the extensor tendons of metacarpophalangeal (MCP-) joints is prevalent in RA and poses a markedly increased risk of RA development when present in arthralgia patients. Such inflammation is called 'peritendinitis' since anatomy literature reports no presence of a tenosynovial sheath at these tendons. However, the presence or absence of tenosynovium at these extensor tendons has never been studied. Therefore, an anatomical and histological study of extensor tendons at the MCP-joints of three embalmed human hands was performed. Immunohistochemical staining showed the presence of markers for synovial macrophages and fibroblast-like synoviocytes bordering a natural dorsal space next to the extensor tendon, suggesting the presence of a synovial lining. This implies that contrast-enhancement on MRI around extensor tendons at MCP-joints observed in early RA and pre-RA likely represents tenosynovitis and that inflammation of this synovial tissue is an early feature of RA.

Carpometacarpal and metacarpophalangeal joint collapse is associated with increased pain but not functional impairment in persons with thumb carpometacarpal osteoarthritis

INTRODUCTION

Due to the complex shape of the carpometacarpal (CMC) joint, a fixed joint collapse deformity of the thumb CMC (CMC1) and metacarpophalangeal (MCP1) joint can present in advanced stages of CMC1 osteoarthritis (OA), resulting in adduction of the first metacarpal (MC1) and hyperextension of the MCP1.

PURPOSE OF THE STUDY

To determine whether joint collapse deformity is associated with worse pain and/or functional impairment.

STUDY DESIGN

Cross-sectional.

METHODS

This study used the baseline data from 140 patients enrolled in a longitudinal study of treatment for CMC1 OA. (efficacy of combined conservative therapies on clinical outcomes in patients with CMC1 OA). Joint collapse was determined at baseline using a pinch gauge. Pain was assessed on a visual analog scale (0-100) and function was assessed using the Functional Index for Hand Osteoarthritis questionnaire (0-30). Pain and function and the presence of joint collapse were entered in a univariate logistic regression. The final adjusted model for pain and joint collapse included age and sex. The final adjusted model for function and joint collapse included Kellgren Lawrence grade and grip strength.

RESULTS

About 20% of participants demonstrated joint collapse on the tip-pinch test. The presence of joint collapse was associated with increased pain in the unadjusted [P = .047, OR = 2.45, 95% CI (1.01, 5.910)] and adjusted model [P = .049, OR = 2.45, 95% CI (1.00, 5.98)].

CONCLUSION

CMC1 patients with joint collapse reported increased pain compared with those without joint collapse. Future studies should determine the relationship between thumb hypermobility and joint collapse and how to manage these conditions effectively.

Innervation of digital joints: an anatomical overview

INTRODUCTION

The innervation of the digital joints as well as the anatomical relationships of the articular branches is present in this anatomical work to determine the technical feasibility of a selective and efficient denervation of the digital joints.

MATERIALS AND METHODS

A study of 40 distal interphalangeal (DIP), 40 proximal interphalangeal (PIP), 50 metacarpophalangeal (MCP), 10 interphalangeal (IP) of the thumb, and 10 trapezo-metacarpophalangeal (TMC) joints was performed on ten hands. Under magnification and a proper surgical approach, we collected the course, the source origin, the number of articular nerve branches, and their caliber.

RESULTS

In total, 118 nerve branches arising from the proper palmar digital nerves were found on 10 DIP of each dissected long finger (n = 40). A total of 226 nerve branches were found on 10 PIPs of each long finger (n = 40), of which 204 branches (90.3%) had a palmar origin. Dorsal innervation was found for the ring and little finger, originating from the dorso-ulnar digital nerve. 212 branches were found on 10 MCP of long fingers (n = 40), including 87 branches of palmar origin (41.1%), 107 branches of dorsal origin (50.4%), and 18 branches of the motor branch of the ulnar nerve (8.5%). 42 articular branches directed to the TMC joint (n = 10) were found. 13 branches (31%) originated from the anterior sensory branch of the radial nerve, 13 branches (31%) originated from the lateral cutaneous nerve of the forearm, 5 branches (12%) originated from the palmar cutaneous branch of the median nerve, and 11 (26%) branches originated from the thenar branch of the median nerve. The involvement of the sensory anterior branch of the radial nerve was always present for the innervation of each TMC.

DISCUSSION AND CONCLUSION

Our research shows that finger joints receive their primary innervation from small branches of the digital nerves with the exception of the MCP joint and the TMC joint. To obtain an efficient and a selective digital denervation for articular pain relief, it is necessary to plan the best surgical approach and it is crucial to recognize the articular nervous branch localization and source.

The moment arms and leverage of the human finger muscles

The moment arm of a muscle's force represents the muscle's leverage or mechanical advantage in producing a joint moment. It is indicative of the muscle's potential to contribute to actuation of a joint in a particular joint motion direction and defines the role of the muscle, for example, as a joint flexor or abductor. The aims of this study were, firstly, to measure the moment arms of the flexor and extensor muscles of the metacarpophalangeal (MCP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints, and the moment arms of the major abductor and adductor muscles of the metacarpophalangeal (MCP) joint of each finger in the hand; secondly, to assess the effect of change in joint angle on these moment arms; and thirdly, to determine if there are differences in a given flexor or extensor's muscle moment arms between the joints it spans on a given finger, and across its tendon slips to multiple fingers. The tendon-excursion method was used to measure instantaneous muscle moment arms in nine fresh-frozen entire forearm cadaver specimens. Joint flexion angle was found to have significant effects on the moment arms of the extensor muscles at the MCP and PIP joints (p < 0.05). In contrast, the digital flexor muscles maintained relatively constant moment arms through the range of joint flexion. The moment arms of the digital flexors and extensors spanning multiple joints in a finger were largest at the MCP joints and smallest at the DIP joints. The findings demonstrate greater torque generating capacity for tasks such as grasping at the proximal interphalangeal joints, and smaller torque capacity for finer movement control at the distal interphalangeal joints. The dataset generated in this study may be useful in the development and validation of computational models used in surgical planning, and rehabilitation.

Metacarpophalangeal joint instability in trapeziometacarpal osteoarthritis: A systematic review

Thumb metacarpophalangeal instability is commonly found in conjunction with trapeziometacarpal osteoarthritis. If not corrected, it can have detrimental effects on the outcome. The authors describe the two types of metacarpophalangeal deformities - hyperextension and valgus - their pathophysiology and the surgical repair techniques available to surgeons. An algorithm for treating this instability is presented.

Septic Joints: Finger and Wrist

Infections in the joints of the hand and wrist carry the risk of significant morbidity. Common presenting symptoms include joint redness, swelling, and pseudoparalysis that occurs several days following a penetrating trauma. Diagnostic workup should be expedited, including a laboratory evaluation and arthrocentesis. Imaging, including radiographs, ultrasound, computed tomography, and/or MRI, are helpful tools in diagnosis. Once infection is identified, prompt surgical debridement and antibiotics are required. Once the infection has been managed, hand therapy is initiated to decrease the risk of stiffness. Stiffness is the most common complication following infection; additional reported complications include arthritis, ankylosis, and amputation."

The effects of rehabilitation on the outcomes of surgically treated acute and chronic thumb metacarpophalangeal ulnar collateral ligament ruptures

The aim of this study was to compare the outcome of patients who received rehabilitation to those who did not receive it after surgical treatment of acute and chronic tears of the ulnar collateral ligament (UCL) of the thumb. Forty-two patients with an acute UCL injury repaired with two soft mini-anchors to bone insertion sites, and 40 patients with a chronic UCL injury reconstructed with autografts were involved in this study. The patients were divided two subgroups depending on rehabilitation. Patient characteristics were not significantly different between the two groups and subgroups. Range of motion, grip strength and pinch strength were evaluated. There was no significant change in terms of grip and pinch strength in patients with acute UCL injury who received rehabilitation after surgical treatment. However, significantly better results were achieved in flexion, extension, ulnar and radial deviation. There was no significant change in pinch strength in patients with chronic UCL reconstructions, but significantly better results were achieved in grip strength, flexion, extension, ulnar and radial deviation. A rigid MCP splint in patients with acute and chronic UCL tears is effective in preventing early ligament insufficiency.

What does it mean?

Dislocation of the metacarpophalangeal joint is a rare injury. The index finger is most frequently involved, followed by the thumb; the little finger is very seldom affected. The Complex dislocation of the little finger metacarpophalangeal joint is extremely rare. A few cases only had been described. Herein, we report a case of 40 years old presented, after a road accident, a dorsal metacarpophalangeal joint dislocation of the litter finger confirmed on radiographs with a clear view of the sesamoid bone within joint prompting the patient to undergo open reduction with no attempts of closed reduction initially. We elected, to treat our case, for the volar approach which allowed successful relocation of the head of the metacarpal in its anatomical position. The view of sesamoid bone within the joint is pathognomonic of volar plate entrapment. Recognition of this fact should alert the treating physician to the inevitability of open reduction for anatomical repositioning of the joint and avoid repeated attempts at closed reduction which may arise the risk of degenerative arthritis and reduced final range of motion.

Do trapeziometacarpal prosthesis provide better metacarpophalangeal stability than trapeziectomy and ligamentoplasty?

BACKGROUND

No surgical management is better than another regarding functional recovery for trapeziometacarpal joint osteoarthritis. Metacarpophalangeal (MCP) hyperextension, directly due to the shortening of thumb height, appears to be a factor of poor prognosis.

HYPOTHESIS

MCP hyperextension can be corrected by implantation of a trapeziometacarpal prosthesis (TMP), as opposed to trapeziectomy and ligamentoplasty (TL), and pinch strength is greater with TMP in this indication.

MATERIAL AND METHODS

Sixty-nine patients (41 TMP and 28 TL) were retrospectively evaluated. The following were evaluated: pain, mobility of the metacarpophalangeal joints, palmar grip and pinch strength. Thumb height was measured on radiographs as a post/preoperative ratio.

RESULTS

The mean follow-up was 20 months (6-38). The TMP group showed greater reduction of the metacarpophalangeal hyperextension in all hyperextension groups, especially hypertension >30°, compared with TL. The TMP group provided significant greater pinch strength in all the subgroups with preoperative MCP hyperextension. Patient with postoperative MCP hyperextension had a significant lower grip and pinch strength compared with patient without MCP hyperextension. Radiographic analysis showed that thumb height changes were related to the degree of preoperative hyperextension. Postoperatively, patients with postoperative MCP hyperextension had a significant lower thumb height than patient without MCP hyperextension.

DISCUSSION

Metacarpophalangeal hyperextension appears to be a factor of poor prognosis for surgical treatment of trapeziometacarpal osteoarthritis when it is not managed. TMP provides better metacarpophalangeal stabilization by restoring thumb length and would avoid surgery on the metacarpophalangeal joint. TMP may be recommended in patients having symptomatic trapeziometacarpal joint osteoarthritis and MCP joint hyperextension.

LEVEL OF EVIDENCE

III, retrospective observational case control study.

Management of posttraumatic finger contractures in adults

This lecture will focus on posttraumatic finger contractures affecting the metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints in adults. The pathophysiology, main causes and essential rehabilitation methods that can be used before resorting to surgical treatment are described, along with the clinical examination. The goal is to define the surgical indications, even though the literature shows the functional outcomes are disappointing. While there is little to no change in a joint's angular amplitude, the functional range of motion can be improved. There is practically no functional improvement except in cases of MCP extension contracture. For the PIP joint, the aim is to shift the range of motion into the functional range. Surgical approaches, surgical techniques and rehabilitation protocols are described in detail.

Metallosis After Swanson Spacer as Indication for Volar Synovectomy 12 Years After Implantation

The treatment of metacarpophalangeal destruction by rheumatoid arthritis is an indication for arthroplasty, the swanson spacer is one of the options. The flexible silicone spacer may be implanted with or without titanium guide sleeves ("grommets"). However, the imaginary abrasion protection for the silicone grommets may in turn lead through micro-movements to wear. A 69 years old female patient suffering from rheumatoid arthritis for 30 years is presented. 12 years ago swansen spacers were implanted to metacarpo-phalangeal joints 2 -5 of the right hand. Due to pain, limited movement and swelling at the volar MCP joints she presented at our clinic. Volar synovectomy of the 3rd ray of the right hand was performed, the A2 ring band could be spared. There was massive metallosis induced by wear of the grommets in the third volar tendon sheath, the other flexors were free of metallosis. These results show that in synovitis after swanson spacer implantation using grommets the differential diagnosis of metallosis must be included and complete synovectomy is the treatment of choice.

Still a challenge for the hand surgeon?

OBJECTIVES

The aim of this study is to analyse the outcomes of the surgical treatment of metacarpophalangeal stiffness by dorsal teno-arthrolysis in our centre, and present a review the literature.

MATERIAL AND METHODS

This is a retrospective study of 21 cases of metacarpophalangeal stiffness treated surgically. Dorsal teno-arthrolysis was carried out on all patients. A rehabilitation programme was started ten days after surgery. An evaluation was performed on the aetiology, variation in pre- and post-operative active mobility, complications, DASH questionnaire, and a subjective satisfaction questionnaire.

RESULTS

The mean age of the patients was 36.5 years and the mean follow-up was 6.5 years. Of the 21 cases, the most common cause was a metacarpal fracture (52.4%), followed by complex trauma of the forearm (19%). Improvement in active mobility was 30.5°, despite obtaining an intra-operative mobility 0-90° in 80% of cases. Mean DASH questionnaire score was 36.9 points. The outcome was described as excellent in 10% of our patients, good in 30%, poor in 40%, and bad in the remaining 20%. There was a complex regional pain syndrome in 9.5% of cases, and intrinsic muscle injury in 14.3%.

CONCLUSION

Because of its difficult management and poor outcomes, surgical treatment of metacarpophalangeal stiffness in extension is highly complex, with dorsal teno-arthrolysis being a reproducible technique according to our results, and the results reported in the literature.

Type I locking of the metacarpophalangeal joint: A case report

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The locked metacarpophalangeal joint is rare.

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We present an unusual case with impingement to the sesamoid.

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Differential diagnosis and management are discussed.

Introduction

Type I locking of the metacarpophalangeal joint (MCPJ) is rare and is characterized by loss of extension at the MCPJ with full flexion of all joints of the digit. The condition is usually seen in the index and middle fingers when the normal osseous prominence or degenerative osteophytes of the radial condyle of the metacarpal head catches the accessory collateral ligaments of the MCPJ.

Presentation of case

We report on a case of Type I locking of the MCPJ affecting the index finger. The case was unusual because it might have been related to repeated stress while opening caps of specimen bottles in the laboratory. Furthermore, the impingement of the radial condyle of the metacarpal was to the sesamoid bone, and not to the collateral ligaments of the MCPJ. Finally, management was done by excision of the sesamoid bone rather than trimming of the prominence of the radial condyle of the metacarpals head.

Discussion

Locking of the metacarpophalangeal joint (MCPJ) should be viewed as two different entities: The “locked MCPJ with further flexion possible” (Type I locking) and the “locked MCPJ with further flexion not possible” (Type II locking). Once the type of MCPJ locking is diagnosed clinically, radiological testing (X-rays, CT scan, MRI) may be done to direct further management to the cause of locking.

Conclusion

We present an unusual case of Type I locking of the MCPJ affecting the index finger.

Floating thumb metacarpal in a motorcyclist: A case report

We present a case of simultaneous dislocation of the carpometacarpal and the metacarpophalangeal joints of the thumb (floating thumb metacarpal) in a 47-year-old motorcyclist. The treatment consisted of closed reduction of both joints with cast immobilization. After 24 months, the functional result was excellent. The mechanism of this rare injury and its therapeutic management are discussed.

Simultaneous Volar Dislocations of Carpometacarpal and Metacarpophalangeal Joints of the Thumb

INTRODUCTION

Multiple dislocations of joints in the hand are rare. Double dislocations of the thumb joints have only been reported on four previous occasions, in all cases reported to date, the joints have dislocated dorsally.

CASE REPORT

We present the case of a 26-year-old male patient with simultaneous volar dislocations of the carpometacarpal and metacarpophalangeal joints of the thumb. There was delayed operative treatment of this injury with ligament reconstruction and stabilization of the metacarpophalangeal joint.

CONCLUSIONS

This rare case provides a mechanism to this type of injury, highlights the importance of initial, and repeated clinical and radiographic review, highlights the soft tissue component to this injury, and demonstrates how even delayed treatment can result in a good functional outcome.