Lesser metatarsophalangeal instability: presentation, management, and outcomes

Distal Metatarsal Segmental Shortening for the Treatment of Chronic Metatarsophalangeal Dislocation of Lesser Toes

BACKGROUND

This retrospective study aimed to describe the techniques and results of distal metatarsal segmental shortening (DMSS) for the treatment of chronic irreducible metatarsophalangeal (MTP) dislocation of lesser toes.

METHODS

We retrospectively reviewed patients who underwent DMSS for chronic dislocation of MTP joints of lesser toes between January 2010 and December 2017 with follow-up of at least 24 months. Demographic data, radiographic measurements, functional outcomes, and complications were analyzed. Furthermore, the results of patients with short segment of shortening (group I, <10 mm) were compared to those with long segment of shortening (group II, ≥10 mm). A total of 43 MTP joints of 30 patients with an average age of 70.4 years were included.

RESULTS

Union was observed in 42 metatarsals (97.7%). Mean American Orthopaedic Foot & Ankle Society scale scores improved significantly from 42.2 (range, 15-65) preoperatively to 79.1 (range, 52-90) (P < .001). Mean visual analog scale pain score improved significantly from 5.0 (range, 1-9) preoperatively to 1.8 (range, 0-6) (P < .001). Complications included 1 nonunion, 1 osteonecrosis, 3 metatarsal angulation, 4 recurrent instability, 4 symptomatic osteoarthritis, 3 transfer metatarsalgia, and 1 floating toe. Group I included 23 MTP joints and group II included 20 MTP joints. There was no significant difference in clinical outcomes and complications between the 2 groups.

CONCLUSION

DMSS was a reliable procedure for the treatment of chronic irreducible dislocated MTP joint of lesser toes. It provided satisfactory surgical outcomes and a low rate of postoperative complications, regardless of length of metatarsal shortening.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Lesser Metatarsophalangeal Instability: Diagnosis and Conservative Management of a Common Cause of Metatarsalgia

CONTEXT

Lesser metatarsophalangeal (MTP) instability is a common condition that can become debilitating and require surgery.

EVIDENCE ACQUISITION

An extensive literature review was performed through MEDLINE and Google Scholar for publications relating to the etiology, diagnosis, and treatment of lesser MTP instability using the keywords metatarsophalangeal instability, athlete, forefoot pain, and metatarsalgia from database inception to 2019.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 4.

RESULTS

Lesser MTP instability is a common condition, especially in the active and aging populations. It is frequently misdiagnosed, causing delays in treatment that allow for progressive pain and deformity, which prevents an active lifestyle. Fortunately, MTP instability can be diagnosed easily with the drawer test. Magnetic resonance imaging is helpful when still in doubt. Conservative treatment entails joint immobilization and gradual return to play with taping and offloading metatarsal pads.

CONCLUSION

Lesser MTP instability is a common diagnosis. Its early detection and conservative treatment can help the patient regain their previous level of activity and avoid surgery.

Use of Metatarsophalangeal Joint Dorsal Subluxation in the Diagnosis of Plantar Plate Rupture

A dorsal drawer exam, also known as a modified Lachman's test, is a common clinical test for plantar plate insufficiency. This disorder presents as a dislocated metatarsophalangeal joint. The aim of this cadaveric case study was to quantify the degree of the plantar plate pathology necessary to correlate with a positive Lachman's test. The second metatarsophalangeal joint was tested on 18 cadaveric lower extremities. Limbs with previous digital surgery or with an obvious digital deformity were excluded from this study. A plantar linear incision over the plantar aspect of the second metatarsophalangeal joint was performed, and the flexor tendons were retracted to expose the plantar plate. After evaluating the plantar plate's integrity and measuring its width, a Lachman's test was then performed under fluoroscopy. The plantar plate was subsequently severed in a serial manner in 2-mm increments. A modified Lachman's test was performed with the different levels of rupture to assess the degree of dislocation. We found that a tear as small as 2 mm, detected in 12 (66.7%) of 18 specimens, produced gross instability in the second metatarsophalangeal joint. We also showed that a simulated plantar plate tear ≥4 mm but <6 mm resulted in joint subluxation (positive modified Lachman's test) with a sensitivity of 90.3%. This study reinforces the finding that a modified Lachman's test is a clinical exam that demonstrates high sensitivity in diagnosing plantar plate insufficiency.

Biomechanical Evaluation of Suture Configurations in Lesser Toe Plantar Plate Repairs

BACKGROUND

Lesser toe metatarsal-phalangeal (MTP) joint instability can be a major source of pain and dysfunction. Instability occurs when there is incompetence of the plantar plate and/or collateral ligaments. Newer operative treatments focus on performing anatomic repairs of the plantar plate. The goal of this study was to compare the biomechanical properties of 3 suture configurations that may be used for plantar plate repairs.

METHODS

Biomechanical analysis of 27 lesser toe plantar plates from fresh frozen human cadavers was completed. The plantar plate was detached from the proximal phalanx, and suture was placed in the distal plantar plate in a horizontal mattress, luggage-tag, or Mason-Allen suture configuration. Cyclic loading followed by load-to-failure testing was performed.

RESULTS

There was a significant difference in peak load-to-failure force between constructs (mattress: 115.53 ± 15.95 N; luggage-tag 102.42 ± 19.33 N; Mason-Allen: 89.96 ± 15.78 N; P = .015). Post hoc analysis demonstrated that the mattress configuration had significantly higher load-to-failure force compared with the Mason-Allen configuration ( P = .004). There were no significant differences between the mattress and the luggage-tag configurations or the luggage-tag and the Mason-Allen configurations. There were no differences in construct stiffness, axial displacement at the time of failure, or number of cycles required to produce 2 mm of displacement.

CONCLUSION

The mattress configuration demonstrated better peak load-to-failure force compared with the Mason-Allen configuration but was not statistically different from the luggage-tag configuration. Although not significant, the mattress configuration trended toward higher load-to-failure force compared with the luggage-tag.

CLINICAL RELEVANCE

The horizontal mattress stitch may be the biomechanically superior configuration in plantar plate repairs.

Lesser Metatarsophalangeal Joint Instability: Treatment with Tendon Transfers

Complex digital deformities and metatarsophalangeal joint instability encompass a wide range of pathology, and we must identify the different degrees of ligamentous disruption. It is important to address a combination of procedures to treat gross deformities of the lesser toes. Surgical treatment should be individualized and requires a sequential process for adequate reduction and deformity correction. There is no gold standard procedure for every deformity. Although residual stiffness can result from tendon transfer, overall patient satisfaction levels remain high when it is performed under the proper indications and concomitantly with other procedures to gain full correction of these challenging deformities.

Lesser Metatarsophalangeal Joint Instability: Advancements in Plantar Plate Reconstruction

The plantar plate and associated collateral ligaments are the main stabilizers of each of the lesser metatarsophalangeal joints. Although clinical examination and plain radiographs are usually sufficient to establish the diagnosis of a plantar plate tear, MRI or fluoroscopic arthrograms may help in specific cases. Recent results with a dorsal approach to plantar plate repair are promising with respect to pain relief and patient satisfaction.

Plantar Plate Repair for Lesser Metatarsophalangeal Joint Instability

BACKGROUND

Lesser metatarsophalangeal (MTP) joint instability is a common cause of forefoot pain. Advances in operative technique and instrumentation have made it possible to anatomically treat plantar plate tears through a dorsal approach. Our goal was to evaluate the subjective, functional, and radiographic outcomes of plantar plate repair (PPR) from a dorsal approach.

METHODS

A prospective case series was performed evaluating the results of PPR in 97 feet with 138 plantar plate tears. Patients underwent PPR from a dorsal approach with a Weil osteotomy. We followed patients at regular intervals for 12 months and collected data preoperatively and postoperatively with respect to visual analog scale (VAS) scores, MTP range of motion (ROM), paper pull-out test, American Orthopaedic Foot & Ankle Society (AOFAS) scores, satisfaction, and radiographic measures.

RESULTS

Eighty percent of patients scored "good" to "excellent" satisfaction scores at 12 months. The mean VAS pain score preoperatively was 5.4/10, and postoperatively was 1.5/10. The mean AOFAS scores increased from 49 to 81 points following surgery. The mean MTP ROM preoperatively was 43 degrees and postoperatively 31 degrees. Forty-two percent of toes passed the paper pull out test prior to surgery and 54% at 12 months. Mean metatarsal shortening was 2.4/3.1/1.2 mm for the second, third, and fourth metatarsals, respectively. The mean MTP joint angles preoperatively were 2/4.9/-1.3 degrees and postoperatively were 7.4/9.6/0.2 degrees, respectively, for the second, third, and fourth MTP joints.

CONCLUSION

We found that the plantar plate could be repaired through a dorsal approach with reliable outcomes. PPR was a viable option to anatomically restore the ligamentous support in the unstable lesser MTP joint.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Metatarsophalangeal joint stability: a systematic review on the plantar plate of the lesser toes

Background

Instability of the metatarsophalangeal (MTP) joints of the lesser toes (digiti 2–5) is increasingly being treated by repair of the plantar plate (PP). This systematic review examines the anatomy of the plantar plate of the lesser toes, and the relation between the integrity of the plantar plates of the lesser toes and lesser MTP joint stability.

Methods

The databases of Embase.com, Medline (Ovid), Web of Science, Scopus, Cochrane, Pubmed not medline, Cinahl (ebsco), ProQuest, Lilacs, Scielo and Google Scholar were searched in June 2015 from inception. Studies were included if they were in English, contained primary data, and had a focus on plantar plate anatomy of the lesser toes or on the relationship between integrity of the plantar plate and MTP joint (in)stability. Study characteristics were extracted into two main tables and descriptive anatomical and histological data were summarized into one schematic 3D drawing of the plantar plate.

Results

Nine studies were included in this systematic review, of which five addressed plantar plate anatomy as such and four focused directly and indirectly on plantar plate integrity related to MTP joint stability.

Conclusion

This is the first systematic review regarding plantar plate anatomy related to MTP joint stability of the lesser toes. This review iterates the importance of plantar plate anatomy and integrity for MTP joint stability, and it delineates the lack of primary data regarding plantar plate anatomy of the lesser toes and MTP joint stability.

Electronic supplementary material

The online version of this article (doi:10.1186/s13047-016-0165-2) contains supplementary material, which is available to authorized users.

Surgical reduction and ligament reconstruction for chronic dorsal dislocation of the lesser metatarsophalangeal joint associated with hallux valgus

BACKGROUND

Hallux valgus (HV) is occasionally associated with chronic dislocation of the lesser metatarsophalangeal (MTP) joints. We have developed a novel surgical procedure to treat dislocation of the lesser MTP joints. This study aimed to describe our procedure and investigate the outcomes of surgical intervention in the treatment of HV with dislocation of the lesser MTP joints.

METHODS

Twenty-three patients (27 feet, average age: 63.6 years, average follow-up: 49.5 months; a minimum follow-up of 24 months) underwent surgical intervention for HV and dislocation of the lesser MTP joints. Twenty-three feet had dislocation (10 feet) or subluxation (13 feet) of the second MTP joint, whereas 4 feet had dislocation of the second and third MTP joints. The surgical procedure included a distal soft-tissue procedure combined with proximal osteotomy for correction of the HV, and reconstruction of the collateral ligaments (CL) following open reduction with complete release of the capsule and the CL at the metatarsal head for dislocation of the lesser MTP joints. Outcomes were assessed using the Japanese Society for Surgery of the Foot (JSSF) scale and radiological examinations.

RESULTS

The JSSF score improved significantly from an average of 49.7 points preoperatively to 93.1 points postoperatively. The average HV angle and intermetatarsal angle decreased significantly from 44.6° and 18.1° preoperatively to 7.9° and 6.0° postoperatively, respectively. The average extension and flexion of the second MTP joint was 53.1° and 13.8° at the most recent follow-up, respectively. Postoperatively, no feet had dislocation of the second or third MTP joint, three had subluxation of the second MTP joint, and one had subluxation of the third MTP joint. Osteoarthritis of the lesser MTP joint had developed in two feet (7.4 %) at the time of the most recent follow-up.

CONCLUSION

Our surgical procedure achieved significant correction of HV, a low rate of postoperative re-dislocation of the lesser MTP joints, and significant improvement of pain and function for symptomatic moderate-to-severe HV with dislocation of the lesser MTP joints.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Deep transverse metatarsal ligament and static stability of lesser metatarsophalangeal joints: a cadaveric study

BACKGROUND

The static support that guides motion around the lesser metatarsophalangeal joints (MTPJs) is complex. Biomechanical studies revealed important roles of both the plantar plane and collateral ligaments. Since part of the plantar plate is attached to the deep transverse metatarsal ligament (DTML), we hypothesized that the transection of the DTML in the intermetatarsal space may substantially reduce the MTPJ stability.

METHODS

The second, third, and fourth MTPJ stabilities of 6 fresh-frozen human cadaveric foot specimens were measured under load control. Both dorsiflexion and dorsal subluxation conditions were tested. After the intact condition was assessed, the DTML was sequentially transected such that each MTPJ had a unilateral and then a bilateral DTML transection. Stiffness data were calculated using the loading range in each test condition. Paired Student t tests were performed to test for statistical significance (P value less than .05).

RESULTS

In intact specimens, the mean stiffness with dorsiflexion of the second, third, and fourth toes was 0.52 ± 0.15 N/deg. When the DTML was operatively transected on one side, the dorsiflexion stiffness significantly decreased 17.3% to an average of 0.43 ± 1.00 N/deg (P < .001). Subsequent transection of the DTML on the other side of each joint resulted in a further significant decrease of 5.8% to an average of 0.40 ± 0.08 N/deg (P < .001). The mean stiffness with dorsal subluxation of the intact second, third, and fourth toes was 3.55 ± 0.66 N/mm. When the DTML was operatively transected on one side, the dorsal subluxation stiffness significantly decreased 16.1% to an average of 2.98 ± 0.64 N/mm (P < .001). Subsequent transection of the DTML on the other side of each joint resulted in a further significance decrease of 7.6% to an average of 2.71 ± 0.48 N/mm (P = .016).

CONCLUSION

The DTML has a significant role in maintaining lesser MTPJ ligament stability. Both unilateral and bilateral DTML transections caused substantial instability of the lesser MTPJ.

CLINICAL RELEVANCE

The DTML is part of the natural static restraint to dorsiflexion or dorsal subluxation of the lesser MTPJ. Operative transection, injury, or degeneration of this ligament may predispose the adjacent MTPJ to instability.

Small joint arthroscopy in foot and ankle

The clinical application of small joint arthroscopies (metatarsophalangeal joint, Lisfranc joint, Chopart joint, and interphlangeal joint) in the foot has seen significant advancements in the past decades. This article reviews the clinical indications, technical details, outcomes, and potential complications of small joint arthroscopies of the foot.

Influence of common associated forefoot disorders on preoperative quality of life in patients with hallux valgus

BACKGROUND

Hallux valgus (HV) is frequently associated with other forefoot disorders, but its influence on preoperative quality of life (QOL) has not been well characterized. The main purpose of this study was to assess the influence of common associated forefoot disorders (metatarsalgia and lesser toe deformities) on preoperative QOL in patients with HV.

METHODS

Preoperative QOL assessed through the Short Form-36 (SF-36, version 2) was obtained from 94 patients with HV from a database. Patients were classified according to their condition: HV alone, HV and metatarsalgia, HV and lesser toe deformities, and HV and both metatarsalgia and lesser toe deformities. Values of each domain were compared among groups. In addition, a correlational study between SF-36 and radiographic severity of HV was performed. The mean age of the 94 patients was 62.6 ± 12.3 years. There were 42.6% patients with HV alone, 30.8% with HV and metatarsalgia, 16% with HV and lesser toe deformities, and 10.6% with HV and both metatarsalgia and lesser toe deformities.

RESULTS

Patients with HV and associated metatarsalgia and lesser toe deformities had significantly worse physical function (P = .029), role-physical (P = .017), bodily pain (P = .045), role-emotional (P = .016), mental health (P = .001), and mental component summary (P = .003) compared to patients with HV alone. There were no significant correlations between radiographic HV and intermetatarsal angles and any of the domains or summaries of the SF-36.

CONCLUSION

Patients with HV and both metatarsalgia and lesser toe deformities have significantly worse QOL compared to patients with HV alone. The presence of associated forefoot deformities may be a discriminating factor for the prioritization of surgical treatment of HV.

LEVEL OF EVIDENCE

Level III, cross-sectional study.