Introduction

Rupture of the ACL of knee affects over 175,000 patients a year worldwide.¹ It impairs the stability of the knee, resulting in difficulty with athletic performance. There is also an increased risk of meniscal injury and oateosarthritis if ACL tear is left untreated.² The ACL has a poor capacity of healing compared to other ligaments such as medial collateral ligament, even with suture repair. Therefore, suture repair of the ligament is obsolete nowadays and almost universal treatment is by reconstruction.³ There are various grafts evaluated for ACL reconstruction purpose, of which Semitendinosus gracilis has been found to be most efficient. However, even with this technique, significant problems have been reported. Associated morbidities with harvesting the graft in short term to premature degeneration of the joint in long term have been reported from various studies worlwide.⁴ However, Studies evaluating the efficiency of ST-G graft for ACL reconstruction in India are limited.

The aim of the present study was to evaluate the performance of ST-G graft in ACL reconstruction and to study the associated morbidities in short term follow-up. Evaluation of hamstring strength following use of semitendinosus and gracilis graft to reconstruct ACL was also done.

Methodology

This prospective observational study was conducted in Kamineni Hospital, Hyderabad from November 2004 to May 2005. The study included subjects with clinically confirmed ACL rupture who underwent ACL reconstruction with semitendinosus and gracilis quadruple graft with distal titanium endobuters and tractopexy proximally (ST-G Graft) during the study period. The inclusion criteria were 1) clinically confirmed ACL rupture; 2) No pervious ligament reconstruction done; 3) Healthy contra lateral knee; 4) No diagnosis of re-injury during the follow-up period.

Surgical technique

Rehabilitation

Assessment and Evaluation

Results

Total 20 patients were included in the study of which 19 were males and one subject was female. The mean age of the study group was 24.35 years (range: 18-34 years). Of the twenty subjects, 12 had left ACL reconstruction and 8 had undergone right ACL reconstruction.

Range of motion- The average flexion of the knee at first and third month of follow-up was 44.5⁰ (range: 10⁰-90⁰) and 115⁰ (range: 90⁰-140⁰) ^{respectively. We were able to follow-up only two of the study subjects at 6th post-op month. The range of motion for these two subjects was 1300 and 1400 respectively.}

Power evaluation- The study subjects were evaluated for power at 3^rd and 6^th post-op months. The mean power at 3^rd month was 4.7 kg (range: 4kg-6kg). The two subjects followed up at 6^th month had power of 6kg and 8kg respectively.

Discussion

Arthroscopic assisted intra-articular reconstruction with or without extra-articular reconstruction is the treatment of choice of ACL reconstruction. Surgical reconstruction of the ACL involves various technical factors such as graft selection, positioning, fixation, tensioning and avoidance of stress risers. Three basic types of materials are available for intra-articular reconstruction-autograft, allograft and prosthetic ligament. Allograft tissue carries the risk of disease transmission and delayed biologic incorporation. With high cost and limited availability of prosthetic grafts, autograft stay the most opted graft for ACL reconstruction. However, significant problems do arise even in this procedure. The morbidities associated with graft harvest are donor site pain, hamstring weakness and saphenous nerve damage.⁵

The various autograft materials available are bone patellar tendon bone graft, double looped semitendinosus tendon graft, cigarette rolled fascia lata graft, combined semitendinosis and iliotibial band and combined semitendinosus and gracilis tendon graft.⁶ In the present study, we evaluated the use of ST-G in ACL reconstruction and the morbidities associated with the technique.

The most common complication reported with ST-G graft is hamstring weakness. Various studies worldwide have shown that although there is decreased hamstring strength initially, there was not much difference in the strength index of hamstrings at 2 years of follow up.^{5, 7} Some studies have reported almost complete recovery of strength with 9 to 12 months of post-operative period with aggressive physiotherapy.^{8, 9} Similarly in the present study, we found that most of the study subjects had regained hamstring strength by third post-op month.

Some studies have reported moderate anterior knee pain with ST-G reconstruction. Soon et al postulated that early achievement of extension and quadriceps strengthening is responsible this anterior knee pain.⁵ However none of our patients had this complaint.

The morbidity studied in the present study was sensory changes. A study done by Spicer et al reported sensory changes in the front of knee in 50% of the operated patients, of which 86% had sensory deficit in infra-genicular region. Injury to this nerve can occur during skin incision, tendon exposure, tibial drilling, during tendon dissection or during passage of the tendon stripper.¹⁰ In the present study, none of the subjects complained any sensory deficit post-operatively. Strict adherence to the surgical technique prevents this complication.

Conclusion

In the series of evaluation of hamstring strength following ST-G graft to reconstruct ACL, we found that most of the study subjects had regained hamstring strength by 3^rd post-op month. There were no other morbidities reported during the follow-up.

Limitation

Hamstring muscle strength was assessed only manually in the present study. A detailed assessment using ENMG, torque measurement by isokinetic testing and cybex II testing would help in a more accurate hamstring strength assessment.