Comparison of failure rates and functional outcomes between hamstring autografts and hybrid grafts in anterior cruciate ligament reconstruction: A systematic review and meta-analysis

No increased complication rate with the use of soft tissue quadriceps tendon autograft for primary ACL reconstruction - a systematic review

BACKGROUND

The autograft of choice for anterior cruciate ligament reconstruction (ACLR) remains debateable. Recently there has been increased popularity of soft tissue quadriceps tendon (s-QT) autograft due to less donor site morbidity, reduced anterior knee pain and comparable re-operation and complication rates. The aim of this review was to analyse functional outcomes of primary ACLR using s-QT in adult population without the bone plug and to report its complication profile against other autografts.

PATIENT AND METHODS

This systematic review was performed in accordance with PRISMA guidelines and a review of literature was conducted on four online databases (Medline, EMBASE, Cochrane and Google Scholar). Clinical studies reporting on patients undergoing primary ACLR with s-QT autograft or in comparison to BPTB or HS autografts with a minimum of 6 months follow-up were included. The studies were inclusive of only all soft tissue QT autograft regardless of the implants or fixation method used. Critical appraisal of studies was conducted using the Methodological Index for Non-Randomized Studies (MINORS) tool.

RESULTS

Fourteen studies were eligible. There were three randomised control studies (RCT) and 11 non-randomised comparative studies with 1543 patients who underwent ACLR. 682 underwent s-QT, 498 had hamstring tendon (HT) and 174 had bone-patellar tendon-bone (BPTB). 60% (n = 930) were males and mean follow up was 23.6 months (6-65). Eight studies reported post-operative patient reported outcome measures (PROMs). The mean International Knee Documentation Committee (IKDC) score was 91.5 ± 15.1 whereas mean Lysholm score was 90 ± 3.9. Five studies reported on laxity with mean anterior tibial translation (ATT) of 1.28 ± 1.09 mm. Overall complication rate of s-QT ACLR was 6% with 3% graft failure, 0.52% arthrofibrosis, 0.2% infection, 0.75% revision ACLR. There was no significant difference in functional outcome scores, knee stability and range of motion (ROM) between s-QT, HT and BPTB.

CONCLUSION

s-QT for ACLR has a comparable functional outcome, laxity, failure and with overall graft failure rate of 3%.

LEVEL OF EVIDENCE

III; Systematic review and meta-analysis.

Predicting the Hamstring Graft Size for ACL Reconstruction Using a 3D Tendon Model in Preoperative MRI

Background: Rupture of the ACL is a common injury among men and women athletes. While planning the surgical ACL reconstruction procedure, the eventual graft's diameter is extremely important. Many parameters are therefore evaluated pre-surgery to ensure access to reliable data for estimating the graft diameter. Considering this, magnetic resonance imaging (MRI), particularly qualitative analyses of the hamstring tendons, offers a promising approach. Methods: In a retrospective analysis, we carried out 3D segmentation of the gracilis (GT) and semitendinosus tendon (ST) utilizing MRI with varying slice thicknesses and field strengths. The cross-sectional area (CSA) was calculated on different levels (by relying on the models we had thus created) to generate a mean of CSA with six specific segments. We then correlated the mean CSA with the diameter of the graft measured during surgery. Results: A total of 32 patients were included (12 female, 20 male) in this retrospective analysis. We observed the largest CSA in segment 10 mm-0 (16.8 ± 6.1) with differences between men and women. The graft size and tendon diameter correlated significantly in all segments throughout our study cohort. The strongest correlation was apparent in the segment 10 mm-0 (r = 0.552). Conclusions: MRI-based 3D segmentation and the STGT CSA represent a reliable method for estimating preoperatively a quadrupled hamstring graft diameter. The 10 mm-0 mm segment above the joint line showed a strong correlation, making it an ideal reference for graft planning.

In proximal tibial anterior closing wedge (slope changing) osteotomy lower starting points imply larger bone resection

BACKGROUND

Anterior closing wedge osteotomy (ACWO) for tibial slope correction is a validated procedure in revision anterior cruciate ligament reconstruction (ACLR). This study aims to determine how different starting points of the osteotomy affect the amount of bone resection in ACWO.

HYPOTHESIS

We hypothesized that the lower osteotomy starting points in ACWO imply larger bone resection.

PATIENTS AND METHODS

A total 52 patients who underwent ACWO using infra-tuberosity technique in our institution were included in this study. Each of patients was simulated using additional two separate methods (based on osteotomy level: supra- and trans-tuberosity) based on lateral calibrated pre-operative X-rays of the whole tibia according to the post-operative correction angle. The resection height of the closing wedge, which corresponded to the base of the osteotomy, was measured and compared among the three groups.

RESULTS

The mean actual pre-operative proximal posterior tibial angle (PPTA) was 75.8 ± 2.0°. Post-operatively, PPTA was 84.0 ± 0.6°, and correction angle was 8.2 ± 2.2°. The mean resection height in the supra-tuberosity group was 7.5 ± 0.2 mm, 8.0 ± 2.1 mm in the trans-tuberosity group, and 9.2 ± 2.1 mm in the infra-tuberosity group. There were significant differences between each approach (p ≦ 0.0001). Resection height was moderate positively correlated with the starting point of osteotomy (r = 0.33, 95%CI: 0.18-0.46, p < 0.0001).

CONCLUSION

This study suggests that selecting a distal starting point for the osteotomy in ACWO is directly proportional to the observed increase in bone resection, providing valuable insights for pre-operative planning. These findings are clinically relevant and will aid in preoperatively deciding approach in ACWO.

LEVEL OF EVIDENCE

IV; retrospective case-control study.

Muscle composition is not a prognostic factor for muscle strength recovery after anterior cruciate ligament surgery by hamstring tendon autograft

PURPOSE

For the athlete, anterior Cruciate Ligament (ACL) rupture and its surgical management are often a turning point in their career. Success and time to return to sport are essential parameters for athletes and their support staff, so it is critical to understand the prognostic factors influencing return to sport after anterior cruciate ligament reconstruction (ACLR). The aim of this study was to determine the influence of hamstring muscle composition on muscle power following ACLR with autogenous hamstring grafts.

METHODS

24 patients with chronic torn ACL were included at a single-center over a period of 17 months. They underwent surgical repair and during this procedure grafts were harvested from the gracilis and the semitendinosus. Muscle composition was assessed on the remaining proximal part of the semitendinosus muscle, which is usually discarded, by immunostaining. Muscle power was defined by comparing the strength of the operated leg and the healthy leg on an isokinetic dynamometer at 6 months according a standardized protocol after 6 months of outpatient rehabilitation. Various other intrinsic and extrinsic factors were also studied, such as body mass index (BMI), age, sex, smoking, or sport practiced, to determine factors influencing isokinetic strength test after ACLR.

RESULTS

No statistical relationship was identified between muscle composition and the muscle power between the operated and healthy leg. Smoking and female gender were associated with worse muscle recovery. Age and BMI had no influence on isokinetic performance at 6 months.

CONCLUSION

Following ACLR muscle composition is not associated with difference in strength between the two legs at 6 months. Determining muscle fiber composition of the patient does not inform the rehabilitation protocol or predict muscle strength recovery. Larger series data is required to understand the influence of gender or tobacco on muscle fiber characteristic.

LEVEL OF EVIDENCE

I; Prospective prognostic study.

Anterior cruciate ligament reconstruction with six and eight-strand hamstring tendon autografts produces adequate graft dimensions and functional outcomes: A systematic review

PURPOSE

This study aims to summarize the graft dimensions, failure rates, return-to-sport rates and patient-reported outcome measures (PROMs) following anterior cruciate ligament reconstruction (ACLR) with six or eight-strand hamstring tendon autografts (6SHG or 8SHG).

METHODS

Three databases were searched from inception to 12 February 2024. The authors adhered to PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. All clinical studies reporting patient demographics, objective clinical outcomes and PROMs following ACLR with 6SHG or 8SHG were included for data synthesis. PROMs included the International Knee Documentation Committee (IKDC), Lysholm and Tegner scores.

RESULTS

Thirteen studies comprising 1103 patients were included (mean age: 30.6 years). The transtibial technique was used in all studies, except one study using anatomic ACLR (n = 38), and one study using transtibial and all-inside ACLR (n = 41). Eight studies comprising 512 patients used 6SHG, four studies comprising 507 patients 8SHG and two studies comprising 97 patients used either. Mean graft diameters ranged from 8.0 to 9.2 mm (6SHG) and 9.1 to 9.9 mm (8SHG). Mean graft lengths for 49 6SHG patients ranged from 60.0 to 83.3 mm. The failure rate for 817 patients (6SHG or 8SHG) was 4.8% (0.0%-20.0%). The return-to-sport rate for 112 patients (6SHG or 8SHG) was 75.9% (69.7%-100.0%). Mean IKDC, Lysholm and Tegner scores for 6SHG or 8SHG were 88.4 (86.1-96.3), 91.7 (90.4-96.5) and 6.9 (6.5-7.3), respectively.

CONCLUSIONS

Both 6SHG and 8SHG produced graft diameters <8 mm. Data regarding PROMs suggested good patient satisfaction based on established criteria. Re-rupture and return-to-sport rates were 4.8% and 75.9%, respectively.

LEVEL OF EVIDENCE

Level IV.

Comparison of the retear rate 2years after ACL reconstruction with the Tape Locking Screw short graft system and the STG technique: A case control study with propensity score matching

PURPOSE

Theoretically, short semitendinosus grafts result in less pain and morbidity while providing greater knee flexion strength and sparing the gracilis tendon. They often require the use of blind bone tunnels as well as fixation at both ends of the graft with suspensory cortical buttons. The "Tape Locking Screw" (TLS) system is another option. There are few studies comparing ACL reconstruction with a short graft using the 4-strand semitendinosus graft (ST4-TLS) technique with that of the semitendinosus-gracilis (STG) procedure. This study was designed: (1) to compare the retear rate following these two technics after 2years of follow-up, (2) to compare the clinical scores, complications and return to sport times between the two procedures Q1, Q2.

HYPOTHESIS

Our hypothesis was that there would be no differences in retear rates between the two techniques.

METHODS

This single center case control study included 290 patients who underwent STG reconstruction that were paired by propensity score matching to 299 patients who underwent ST4-TLS reconstruction. The main evaluation criterion was the retear rate 2years after surgery. Secondary criteria were the two-year postoperative complication rate, the time to return to sport, to pivot sports and to running, as well as the complication rates and clinical scores 6months, 1year and 2years after surgery.

RESULTS

At the final follow-up, the overall retear rate in our series of ACL ligament reconstruction was 6.0% (36/596). There was no difference in retear rates between the groups 2years after ligament reconstruction [ST4-TLS: 6.7% (20/299) vs. STG: 5.4% (16/297); p=0.47]. The postoperative KOOS symptom score and the Tegner score were found to be better in the STG group at 1year (81 vs. 78, p=0.008) and 2years (5.64 vs. 5.10, p=0.016), respectively, representing the minimally clinically important difference (MCID) for the latter. No difference was found in the other clinical scores 6months, 1year or 2years after surgery. There was no significant difference in the return to sport [TLS: 93.0% (164/299) vs. STG: 93.0% (158/297) p=0.99] or the complication rate [TLS: 8.7% (26/299) vs. STG: 7.4% (22/297) p=0.89] between the groups.

DISCUSSION

The ST4-TLS ACL ligament reconstruction technique was found to be as reliable as the standard STG procedure 2years after surgery for the retear rate and the return to sport, although the results of certain postoperative clinical scores seem to be lower.

LEVEL OF EVIDENCE

III; case control study.

Tendon cross-sectional area on magnetic resonance imaging and anthropometric characteristics can be used to predict insufficient four-strand hamstring autograft diameter in anterior cruciate ligament reconstruction: A systematic review

PURPOSE

To evaluate the utility of semitendinosus tendon (ST) and gracilis tendon (GT) cross-sectional area (CSA) on magnetic resonance imaging (MRI) and anthropometric characteristics in preoperative estimation of graft diameter in patients undergoing anterior cruciate ligament reconstruction (ACLR) with four-strand hamstring autografts.

METHODS

Three databases were searched on 29 August 2023. The authors adhered to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and R-AMSTAR (Revised Assessment of Multiple Systematic Review) guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. Data on demographics, anthropometric characteristics, imaging techniques, tendon CSA, correlation coefficients, sensitivities, specificities, regression models and cutoffs for predicting intraoperative graft diameters above 8 mm were recorded.

RESULTS

Forty-six studies comprising 4140 patients were included. Twelve of 19 (63.2%) studies reporting on ST + GT CSA found a moderate to very high correlation with intraoperative graft diameter. Five of 10 (50%) and one of seven (14.3%) studies reporting on ST CSA and GT CSA, respectively, found a moderate to high correlation with intraoperative graft diameter. Cutoffs of ST + GT CSA for predicting graft diameters above 8 mm ranged from 15.8 to 31.2 mm2. Nine of 35 (25.7%) studies that reported on height found a moderate to very high correlation with graft diameter. Seven of 33 (21.2%) studies reporting on weight found a moderate correlation with graft diameter.

CONCLUSION

Of the MRI parameters assessed, ST + GT CSA was the most reliable predictor of graft diameter. However, cutoffs, sensitivities, and specificities for predicting diameters above 8 mm were highly variable. Anthropometric characteristics in general were less predictive of graft diameter than MRI parameters. This information can be used by clinicians to predict patients at risk for ACLR failure due to insufficient graft size.

LEVEL OF EVIDENCE

Level IV.

Peroneus longus tendon autograft versus allograft in revision ACLR: A retrospective comparison

PURPOSE

The use of peroneus longus tendon (PLT) autografts in primary anterior cruciate ligament reconstruction (ACLR) has increased recently, but there is a lack of research on its use in revision ACLR. This study aimed to compare the clinical outcomes and complications between revision ACLR using allografts and PLT autografts.

MATERIALS AND METHODS

Fifty-nine patients who underwent arthroscopic revision of ACLR with complete clinical follow-ups between 2012 and 2021 were retrospectively reviewed. Allograft was used in 44 of these patients, and PLT autograft was used in 15 of them. Lysholm knee score, Tegner activity score, Lachman, and anterior drawer tests were performed after a mean follow-up of 60months (range: 19-116). The American Orthopaedic Foot and Ankle Society (AOFAS) scale was used to evaluate the donor ankle functions. Clinical outcomes and complications were compared between groups.

RESULTS

Both groups showed significantly improved functional outcomes compared to their preoperative assessments. However, both groups had similar clinical results at the final follow-up, including Lysholm knee score, Tegner activity scale, knee range of motion, return to sports, time to return to daily activities, and rate of re-rupture. No major complications were seen in any of the patients. The AOFAS score was 99.13±2.64 in the PLT autograft group without loss of ankle muscle strength, deformity, instability, and permanent iatrogenic neurovascular injuries. The cumulative cost of the allograft group was significantly higher than the PLT autograft group.

CONCLUSIONS

The PLT autograft might be an alternative autograft option to allografts due to similar clinical outcomes, low donor site morbidity, and reduced cost in ACLR revisions, especially if the primary ACLR was performed using grafts harvested around the knee.

LEVEL OF EVIDENCE

III; retrospective comparative study.

Effect of graft types for outcomes in revision anterior cruciate ligament reconstruction: A meta-analysis

PURPOSE

This meta-analysis was performed to compare outcomes among different types of graft for revision anterior cruciate ligament reconstruction (ACLR).

METHODS

A comprehensive search from Embase, PubMed, and Cochrane Library was performed to identify relevant articles. Studies that conducted a comparative analysis on outcomes among different types of grafts were included. A meta-analysis was performed using Review Manager 5.4 software.

RESULTS

In total, 7 non-randomized studies with a minimum 1-year follow-up were included in analysis, and all studies compared outcomes between autograft and allograft. International Knee Documentation Committee subjective knee (IKDC) scores and side-to-side anterior laxity were not significantly different between autograft and allograft. Revision ACLR with allograft had a higher risk of failure than autograft at the final follow-up (OR=2.22, 95% CI=1.55-3.18). The rates of return to pre-injury type of sport and return to same and higher level of pre-injury sport were not significantly different between autograft and allograft.

CONCLUSION

The outcomes of IKDC score, side-to-side anterior laxity, and rates of return to sport were not significantly different between autograft and allograft. Autografts provide a significantly lower risk of failure than allografts in revision ACLR.

LEVEL OF EVIDENCE

IV; meta-analysis.

Though five-strand hamstring autografts demonstrate greater graft diameter, postoperative outcomes are equivocal to four-strand hamstring autograft preparations: a systematic review and meta-analysis of level I and II studies

PURPOSE

To compare graft dimensions, functional outcomes, and failure rates following anterior cruciate ligament reconstruction (ACLR) with either five-strand or four-strand hamstring autograft options.

METHODS

Three databases (MEDLINE, PubMed, and EMBASE) were searched from inception to 22 April 2023 for level I and II studies comparing five- and four-strand hamstring autografts in ACLR. The authors adhered to the PRISMA and R-AMSTAR guidelines as well as the Cochrane Handbook for Systematic Reviews of Interventions. Data on demographics, surgical details and rehabilitation, graft diameter, patient-reported outcome measures (PROMs), and rates of positive Lachman test, positive pivot shift test, and graft rupture were extracted. PROMs included Knee Osteoarthritis and Outcome Score (KOOS) subscales, Lysholm, and International Knee Documentation Committee (IKDC).

RESULTS

One randomized controlled trial (RCT) and four prospective cohort studies with 572 patients were included. Graft diameters were larger in the five-strand group with a mean difference of 0.93 mm (95% CI 0.61 to 1.25, p < 0.001, I2 = 66%). The five-strand group reported statistically higher KOOS ADL subscale and Lysholm scores with a mean difference of 4.85 (95% CI 0.14 to 9.56, p = 0.04, I2 = 19%) and 3.01 (95% CI 0.48 to 5.53, p = 0.02, I2 = 0%), respectively. There were no differences in KOOS symptoms, pain, quality of life, or sports subscales, or IKDC scores. There were no differences in rates of positive Lachman test, positive pivot shift test, or graft rupture with pooled odds ratios of 0.62 (95% CI 0.13 to 2.91, n.s., I2 = 80%), 0.94 (95% CI 0.51 to 1.75, n.s., I2 = 31%), and 2.13 (95% CI 0.38 to 12.06, n.s., I2 = 0%), respectively.

CONCLUSIONS

Although five-stranded hamstring autografts had significantly larger graft diameters compared to four-stranded grafts with a mean difference of 0.93 mm, similar graft rupture rates and clinical laxity assessments were identified following ACLR. While some PROMs were statistically superior in the five-stranded hamstring groups, the threshold for the minimal clinical important difference was not reached indicating similar clinical outcomes overall.

LEVEL OF EVIDENCE

Level II.

No difference in revision risk between autologous hamstring graft less than 8 mm versus hybrid graft 8 mm or larger in anterior cruciate ligament reconstruction

PURPOSE

Hamstring autograft (HA) is commonly used for primary anterior cruciate ligament reconstruction (ACLR). However, if the harvested HA is inadequate in diameter, it is often augmented with an allograft tendon, forming a hybrid graft (HY). This study sought to evaluate aseptic revision risk following HA versus HY ACLR.

METHODS

A retrospective cohort study was performed using data obtained from our healthcare system's ACLR registry. Patients ≤ 25 years of age who underwent primary isolated ACLR were identified (2005-2020). Graft type and diameter size was the primary exposure of interest: < 8 mm HA and ≥ 8 mm HY. A secondary analysis was performed to examine 7 mm HA and 7.5 mm HA vs ≥ 8 mm HY. Propensity score-weighted Cox proportional hazard regression was used to evaluate the risk of aseptic revision.

RESULTS

The study sample included 1,945 ACLR: 548 ≥ 8 mm HY, 651 7 mm HA, and 672 7.5 mm HA. The crude cumulative aseptic revision probability at 8-years for ≥ 8 mm HY was 9.1%, 11.1% for 7 mm HA, and 11.2% for 7.5 mm HA. In adjusted analysis, no difference in revision risk was observed for < 8 mm HA (hazard ratio [HR] 1.15, 95% confidence interval [CI] 0.72-1.82), 7 mm HA (HR 1.23, 95% CI 0.71-2.11), or 7.5 mm HA (HR 1.16, 95% CI 0.74-1.82) compared to ≥ 8 mm HY.

CONCLUSION

In a US-based cohort of ACLR patients aged ≤ 25 years, we failed to observe any differences in aseptic revision risk for HA < 8 mm compared to HY ≥ 8 mm. Augmentation of a HA as small as 7 mm is not necessary to prevent a revision surgery.

LEVEL OF EVIDENCE

Level III.