Technique using interference fixation repair for plantar plate ligament disruption of lesser metatarsophalangeal joints

Lesser Metatarsophalangeal Joint Instability: Open Surgery Treatment Alternatives

Lesser metatarsophalangeal joint plantar plate degeneration and tear typically presents as an attritional pattern of capsuloligamentous deficiency in middle-aged patients or sports-related chronic injuries. Knowledge of the anatomy, pathophysiological basis, common patterns, grading and classification of these injuries, and indications for surgery will aid imaging interpretation in the preoperative setting. The acuity and extent of injury, tissue quality, and functional requirements of the patient influence clinical decision-making with respect to surgical management. This article provides an overview of the open surgical treatment alternatives and the most used techniques to solve instability of the metatarsophalangeal joints.

A Critical Biomechanical Evaluation of Foot and Ankle Soft Tissue Repair

The objective of this article is to review the biomechanical stresses that occur during normal physiologic function of lower extremity soft tissue anatomic structures and to use this as a baseline for a critical analysis of the medical literature because it relates to surgical reconstruction following injury. The Achilles tendon, anterior talofibular ligament, plantar plate, and spring ligament are specifically evaluated.

Operative Management: Plantar Plate

The plantar plate is a vital structure for maintaining lesser metatarsophalangeal joint (MPJ) stability. Its primary role is to provide static stabilization of the MPJs, working in conjunction with the long and short flexor and extensor tendons. When insufficiency or attenuation of the plantar plate occurs, a sagittal plane deformity will slowly develop, eventually leading to a "crossover toe" transverse plane deformity. Coughlin coined this descriptive term to describe the later stages of deformity, most commonly affecting the second MPJ. Shortly after, Yu and Judge elaborated on this condition describing it as "predislocation syndrome," an inflammatory condition affecting the plantar plate causing pain and instability, which could progress to subluxation at the MPJ.

Plantar Plate Repair for Metatarsophalangeal Joint Instability of the Lesser Toes

The plantar plate is a known stabilizer of the lesser toe metatarsophalangeal (MTP) joint. MTP instability is a known common cause of metatarsalgia, most commonly in the second toe. In the last decade, clinical staging and anatomic grading mechanisms have been published to guide the surgeons on the treatment of MTP instability; this has also led to an understanding of how plantar plate tears relate to MTP joint instability. Direct surgical repair of the plantar plate has been described, short-term outcomes have been published, and the results are not perfect, but promising with respect to patient satisfaction and pain relief.

Presence of Neovascularization in Torn Plantar Plates of the Lesser Metatarsophalangeal Joints

BACKGROUND

Recent surgical techniques have focused on anatomic repair of lesser toe metatarsophalangeal (MTP) plantar plate tears, yet it remains unknown whether the plantar plate has the biological capacity to heal these repairs. Therefore, a better understanding of the plantar plate vasculature in response to injury may provide further insight into the potential for healing after anatomic plantar plate repair. Recently, a study demonstrated that the microvasculature of the normal plantar plate is densest at the proximal and distal attachments. The purpose of this study was to compare the intact plantar plate microvasculature network to the microvasculature network of plantar plates in the presence of toe deformity using similar perfusion and nano-computed tomographic (CT) imaging methods.

METHODS

Seven fresh-frozen human cadaveric lower extremities with lesser toe deformities including hammertoe or crossover toe were perfused using a barium solution. The soft tissues of each foot were counterstained with phosphomolybdic acid (PMA). Then using nano-CT imaging, the second through fourth toe metatarsophalangeal joints of 7 feet were imaged. These images were then reconstructed, plantar plate tears were identified, and 11 toes remained. The plantar plate microvasculature for these 11 toes was analyzed, and calculation of vascular density along the plantar plate was performed. Using analysis of variance (ANOVA), this experimental group was compared to a control group of 35 toes from cadaveric feet without deformity and the vascular density compared between quartiles of plantar plate length proximal to distal. A power analysis was performed, determining that 11 experimental toes and 35 control toes would be adequate to provide 80% power with an alpha of 0.05.

RESULTS

Significantly greater vascular density (vascular volume/tissue volume) was found along the entire length of the plantar plate for the torn plantar plates compared to intact plantar plates (ANOVA, P < .001). For the first quartile of length (proximal to distal), the vascular density for the torn plantar plates was 0.365 (SD 0.058) compared to 0.281 (SD 0.036) for intact plantar plates; in the second quartile it was 0.300 (SD 0.044) vs 0.175 (SD 0.025); third quartile it was 0.326 (SD 0.051) vs 0.117 (SD 0.015); and fourth (most distal) quartile was 0.600 (SD 0.183) vs 0.319 (SD 0.082).

CONCLUSION

Torn plantar plates showed increased vascular density throughout the length of the plantar plate with an increase in density most notable in the region at or just proximal to the attachment to the proximal phalanx. Our analysis revealed that torn plantar plates exhibit neovascularization around the site of a plantar plate tear that does not exist in normal plantar plates.

CLINICAL RELEVANCE

The clinical significance of the increased vascularity of torn plantar plates is unknown at this time. However, the increase in vasculature may suggest that the plantar plate is a structure that is attempting to heal.

Update on Investigation Methods for Lower Extremity Biomechanics

Imaging with biomechanical analysis augments the clinical examination and improves outcomes by correlating imaging findings with the examination. Plain film radiographs are the gold standard to assess osseous alignment. The biomechanical examination provides information to formulate an accurate assessment. Weightbearing computed tomography scanning is a potentially valuable for functional information about joint biomechanics. True alignment of the lower extremity can be appreciated on weightbearing computed tomography scanning. Soft tissue structures can be assessed with diagnostic ultrasound examination. Acute and chronic injuries that compromise joint stability can be identified.

Microvasculature of the Plantar Plate Using Nano-Computed Tomography

BACKGROUND:

Lesser toe plantar plate attenuation or disruption is being increasingly implicated in a variety of common clinical conditions. A multitude of surgical techniques and devices have been recently developed to facilitate surgical repair of the plantar plate. However, the microvascular anatomy, and therefore the healing potential in large part, has not been defined. We investigated the microvasculature of the plantar plate by employing a novel technique involving microvascular perfusion and nano-computed tomography (nano-CT) imaging.

METHODS:

Twelve human adult cadaveric lower extremities were amputated distal to the knee. The anterior and posterior tibial arteries were perfused with a barium solution. The soft tissues of each foot were then counterstained with phosphomolybdic acid (PMA). The second through fourth toe metatarsophalangeal (MTP) joints of 12 feet were imaged with nano-CT at 14-micron resolution. Images were then reconstructed for analysis of the plantar plate microvasculature and calculation of the vascular density along the length of the plantar plate.

RESULTS:

A microvascular network extends from the surrounding soft tissues at the attachments of the plantar plate on both the metatarsal and proximal phalanx. The midsubstance of the plantar plate appears to be relatively hypovascular. Analysis of the vascular density along the length of the plantar plate demonstrated a consistent trend with increased vascular density at approximately the proximal 29% and distal 22% of the plantar plate.

CONCLUSION:

There is a vascular network extending from the surrounding soft tissues into the proximal and distal attachments of the plantar plate.

CLINICAL RELEVANCE:

The hypovascular midportion of the plantar plate may play an important role in the underlying pathoanatomy and pathophysiology of this area. These findings may have significant clinical implications for the reparative potential of this region and the surgical procedures currently described to accomplish anatomic plantar plate repair.

Technique and Tips for Multiplanar Correction of Plantar Plate Repairs in Lesser Metatarsophalangeal Joints

Plantar plate repairs are challenging procedures because of the small anatomy of the plantar plate. This can make them daunting, time-consuming procedures to perform. Advances in technology, such as interference screws and small suture passers, have created improved technique possibilities to decrease difficulty, correct multiple planes of deformity, create stronger constructs, and improve patient results. The plantar plate repair technique presented in this article includes a dorsal approach with a metatarsal osteotomy, a knotless repair that provides a strong construct to allow patients to protectively bear weight immediately, and can reduce operative time by presenting tips to quickly navigate the procedure. The presented technique allows for detailed correction of all three planes of deformity, maximizing patient results.

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.

Revision with suture-tape augmentation after failed collateral ligament reconstruction for chronic interphalangeal instability of the hallux

Chronic varus instability or recurrent subluxation following isolated interphalangeal dislocation of the hallux is a rare injury. No consensus has been reached regarding the best joint-salvage procedure for patients with the failed collateral ligament reconstruction using tendon graft. We report a case who achieved satisfactory clinical outcome through a modified surgical procedure (revision collateral ligament reconstruction augmented with suture-tape).

Revision anatomical reconstruction of the lateral ligaments of the ankle augmented with suture tape for patients with a failed Broström procedure

AIMS

The aim of this prospective study was to evaluate the intermediate-term outcomes after revision anatomical ankle ligament reconstruction augmented with suture tape for a failed modified Broström procedure.

PATIENTS AND METHODS

A total of 30 patients with persistent instability of the ankle after a Broström procedure underwent revision augmented with suture tape. Of these, 24 patients who were followed up for more than two years were included in the study. There were 13 men and 11 women. Their mean age was 31.8 years (23 to 44). The mean follow-up was 38.5 months (24 to 56) The clinical outcome was assessed using the Foot and Ankle Outcome Score (FAOS) and the Foot and Ankle Ability Measure (FAAM) score. The stability of the ankle was assessed using stress radiographs.

RESULTS

The mean FAOS and FAAM scores improved significantly to 87.5 (73 to 94) and 85.1 (70 to 95) points at final follow-up, respectively (p < 0.001). The mean angle of talar tilt and anterior talar translation improved significantly to 2.8° (0° to 6°) and 4.1 mm (2 to 7) at final follow-up, respectively (p < 0.001). Side to side comparison in stress radiographs at final follow-up showed no significant difference. The revision failed in one patient who underwent a further revision using allograft tendon.

CONCLUSION

The revision modified Broström procedure augmented with suture tape is an effective form of treatment for recurrent instability of the ankle following a failed Broström procedure. This technique provides reliable stability and satisfactory clinical outcomes at intermediate-term follow-up. Cite this article: Bone Joint J 2017;99-B:1183-9.

Plantar Plate Repair Using a Direct Plantar Approach: An Outcomes Analysis

Direct plantar plate repair using a plantar approach has been described previously, but with few reports of the outcomes or clinical results. The purpose of the present study was to determine the outcomes of this technique. We performed a retrospective analysis of patients who had undergone direct plantar plate repair with or without concomitant Weil osteotomy and a prospective patient-reported subjective outcomes analysis. Ultimately, 131 patients (144 toes) were included, and the response rate for the mailed surveys was 53.5% (77 of 144 toes). The clinical outcomes reported a well-aligned toe in 87.1% of cases, with a recurrence rate of 7.6% (11 of 144) and a revision rate of 2.8% (4 of 144). Statistically significant improvement in the overall modified Foot Function Index (p < .001) and subscale scores for pain (p < .001), disability (p < .001), and activity limitation (p = .001) were noted postoperatively compared with the preoperative data. The median postoperative visual analog pain scale level reported at survey completion was 2.0 (range 0.0 to 10.0; mean ± standard deviation 2.3 ± 2.6). Despite the modified Foot Function Index scores, the patient satisfaction questionnaire data reported mixed results. Our modified Foot Function Index results demonstrated that this approach provides excellent postoperative pain relief, improvement of associated disability, and improvement in activity limitations. The importance of managing patient expectations is acknowledged secondary to the discrepancy with the patient satisfaction data and the modified Foot Function Index results. Further prospective study is warranted to compare this technique with alternate dorsal approaches for plantar plate repair with and without associated commercially available suture passing systems.

Anatomic Repair of Plantar Plate With Flexor Tendon Sheath Reinforcement: Case Series

Plantar plate pathology has gained considerable attention in recent time, and with this increased awareness multiple treatments have been proposed. There have been no comparison studies between these treatments. The authors feel a direct approach for anatomic repair allows for plantar plate repair and tightening to desired tension, without any plantar prominences or potentially irritating hardware. In addition if the plantar plate is found to be attenuated or there is a lack of residual tissue, the described imbrication utilizing the flexor digitorum longus sheath, which is not possible with hardware or newest instrumentation, allows for a robust repair. The presented case series provides results from consecutive patients treated with proposed concurrent plantar and dorsal incisions, providing proof of concept and viability of novel technique.

LEVELS OF EVIDENCE

Level V: Case series.