Surgical technique: Muscle transfer restores extensor function after failed patella-patellar tendon allograft

A Systematic Review of Clinical Outcomes of Pedicled Flap Repairs of the Knee Extensor Mechanism

BACKGROUND

 Rupture of the extensor mechanism of the knee has severe functional morbidity, and repair can be complicated by infection, allograft degeneration, and recurrent rupture. Techniques of autologous tissue repair utilizing pedicled flaps such as the gastrocnemius offer vascularized methods of reconstruction, with potentially diminished complication rates. The goal of this study was to evaluate the functional outcomes and complications associated with pedicled flap repair of the knee extensor mechanism.

METHODS

 A systematic review was conducted following the Preferred Reporting Items for Systemic Reviews and Meta-Analyses guidelines. Publications that focused on local myocutaneous flaps as a means for reconstruction were included. Causes for knee extensor mechanism deficit, flap characteristics, ambulation rate, changes in range of motion pre- and postoperation, and postoperative complications were analyzed. Technique reports including primary suture repairs, synthetic mesh, and allograft use were excluded.

RESULTS

 An initial 119 studies were identified, with final review of 22 observational studies encompassing 128 cases of pedicled flap reconstructions. The gastrocnemius (88.2%, n = 113), quadriceps (6.3%, n = 8), and a combination of the vastus and gastrocnemius flaps (5.5%, n = 7), were the most frequently utilized flaps. Functional outcomes were favorable with 87.2% of patients achieving ambulation without external support. Variability in range of motion outcomes across different flap may be secondary to the patient characteristics as well as extent of initial injury.

CONCLUSIONS

 Autologous pedicle flap reconstruction of the knee extensor mechanism emerges as a viable option for cases characterized by extensive defects and insufficient soft tissue coverage, which are not amenable to direct suture repairs or allografts. Postoperative assessments revealed that the majority of patients experienced improved ambulation status, with no instances of deterioration noted among the patients.

Management Options for Extensor Mechanism Discontinuity in Patients With Total Knee Arthroplasty

Extensor mechanism disruption is one of the most dreaded complications of total knee arthroplasty. At times, the disruption is associated with infection, the paucity of soft tissue, and loosening of implants. Treatment decisions made by surgeons are guided by their experience and expertise. The purpose of this article is to provide the readers with an evidence-based comprehensive review which, in turn, should help them in diagnosis and selecting the best treatment strategy for individual patients. In the following article, we have discussed extensor mechanism disruptions of varying severity at various anatomical levels. We also covered both operative and non-operative measures in different clinical situations. The analysis of various articles published in the literature would also help orthopedic surgeons to understand the probable outcomes of the particular treatment option chosen and to counsel their patients accordingly.

Limb salvage for malignant bone tumours of distal tibia with dual ipsilateral vascularized autogenous fibular graft in a trapezoid-shaped array with ankle arthrodesis and preserving subtalar joint

BACKGROUND

The treatment of malignant tumours of the distal tibia is a challenging surgical problem due to the scarce soft tissue coverage and the instability of the ankle joint that often occurs after resection. However, there is no consensus on the ideal treatment for malignant tumours of the distal tibia.

METHODS

We report a new reconstruction for five patients with high-grade osteosarcoma of distal tibia, using dual ipsilateral vascularized autogenous fibular graft in a trapezoid-shaped array and external fixator, with ankle arthrodesis and preserving subtalar joints. The patients were examined clinically and radiographically.

RESULTS

The average follow-up duration was 88 months. The mean wound healing time was 14 days. Bone healing was achieved for all the five patients at an average time of 7 months. There were no complications of mal-union, skin necrosis, post-operative infection, loss of internal fixation, peroneal nerve injury. One patient had a local recurrence, which required amputation 15 months postoperatively. The remaining four patients were able to walk with an average functional score of 81.25% according to MSTS.

CONCLUSIONS

Our study shows that this technique is safe and effective to perform implantation of dual ipsilateral vascularized autogenous fibular graft in a trapezoid-shaped array and preserving subtalar joints in terms of the distal tibial reconstruction for malignant bone tumour of the distal tibia. This reconstruction represents a biological alternative protocol for limb salvage in cases of malignant bone tumour of the distal tibia, with encouraging results and with the advantages of lower complications and accelerating recovery.

LEVEL OF EVIDENCE

Level IV.

Patellar tendon reconstruction using an extended gastrocnemius flap following cryogenic injury to the knee

Cryogenic thermal necrosis after knee surgery is rare. We describe a patient who presented with an anterior knee soft tissue defect in conjunction with an extensor mechanism deficiency secondary to a cold thermal injury after an anterior cruciate ligament reconstruction. We treated the patient with a single stage surgical procedure combining patellar tendon reconstruction and soft tissue coverage utilizing the superficial portion of the patient's vascularized Achilles tendon attached to a medial gastrocnemius flap. The patient returned to unrestricted activities and has demonstrated this through a five year follow-up.

Extensor tendon ruptures after total knee arthroplasty

Extensor tendon rupture is a rare but serious complication after total knee arthroplasty (TKA) that impairs active knee extension, thereby severely affecting knee function. Surgery is usually required. Surgical options range from simple suturing to allograft reconstruction of the entire extensor mechanism and include intermediate methods such as reconstruction using neighbouring tendons or muscles, synthetic ligament implantation, and partial allograft repair. Simple suturing carries a high failure rate and should therefore be routinely combined with tissue augmentation using a neighbouring tendon or a synthetic ligament. After allograft reconstruction, outcomes are variable and long-term complications common. Salvage procedures for managing the most severe cases after allograft failure involve reconstruction using gastrocnemius or vastus flaps. Regardless of the technique used, suturing must be performed under tension, with the knee fully extended, and rehabilitation must be conducted with great caution. Weaknesses of available case-series studies include small sample sizes, heterogeneity, and inadequate follow-up duration. All treatment options are associated with substantial failure rates. The patient should be informed of this fact and plans made for a salvage option. Here, the main techniques and their outcomes are discussed, and a therapeutic strategy is suggested.