Comparison of knee flexor strength recovery between semitendinosus alone versus semitendinosus with gracilis autograft for ACL reconstruction: a systematic review and meta-analysis.

BACKGROUND: Whether there is a difference in harvesting the semitendinosus tendon alone (S) or in combination with the gracilis tendon (SG) for the recovery of knee flexor strength after anterior cruciate ligament (ACL) reconstruction remains inconclusive. Therefore, this study aimed to assess the recovery of knee flexor strength based on the autograft composition, S or SG autograft at 6, 12, and ≥ 24 months after ACL reconstruction. METHODS: A systematic review and meta-analysis was conducted following the PRISMA guidelines. A comprehensive search was performed encompassing the Cochrane Library, Embase, Medline, PEDRo and AMED databases from inception to January 2023. Inclusion criteria were human clinical trials published in English, comprised of randomized controlled trials (RCTs), longitudinal cohort-, cross-sectional and case-control studies that compared knee flexor strength recovery between S and SG autografts in patients undergoing primary ACL reconstruction. Isokinetic peak torques were summarized for angular velocities of 60°/s, 180°/s, and across all angular velocities, assessed at 6, 12, and ≥ 24 months after ACL reconstruction. A random-effects model was used with standardized mean differences and 95% confidence intervals. Risk of bias was assessed with the RoBANS for non-randomized studies and the Cochrane RoB 2 tool for RCTs. Certainty of evidence was appraised using the GRADE working group methodology. RESULTS: Among the 1,227 patients from the 15 included studies, 604 patients received treatment with S autograft (49%), and 623 received SG autograft (51%). Patients treated with S autograft displayed lesser strength deficits at 6 months across all angular velocities d = -0.25, (95% CI -0.40; -0.10, p = 0.001). Beyond 6 months after ACL reconstruction, no significant difference was observed between autograft compositions. CONCLUSION: The harvest of S autograft for ACL reconstruction yields superior knee flexor strength recovery compared to SG autograft 6 months after ACL reconstruction, irrespective of angular velocity at isokinetic testing. However, the clinical significance of the observed difference in knee flexor strength between autograft compositions at 6 months is questionable, given the very low certainty of evidence and small effect size. There was no significant difference in knee flexor strength recovery between autograft compositions beyond 6 months after ACL reconstruction. TRIAL REGISTRATION: CRD42022286773.

Suture Augmentation of a Four-Strand Semitendinosus Graft Improves Time-Zero Biomechanical Properties.

PURPOSE: To compare the time-zero biomechanical properties of hamstring graft preparations with or without suture augmentation for anterior cruciate ligament reconstruction (ACLR) in a full-construct cadaveric model. METHODS: Hamstring grafts were harvested from 24 fresh frozen human cadavers and prepared in 1 of 3 ways: quadrupled SemiTendinosus (SemiT), and quadrupled SemiT with suture augmentation (SemiT+2.0-mm tape or SemiT+1.3-mm tape; n = 8 per group). Adjustable loop suspensory implants and cortical buttons were used for fixation on a porcine tibia and acrylic block. Testing included force-controlled cyclic loading at 250 N and 400 N followed by load to failure. RESULTS: The 2 suture augmentation groups had less total elongation and increased stiffness compared to the nonsuture-augmented group (P = .025). The SemiT+2.0-mm tape group had 36% less total elongation and 34% increased stiffness compared to SemiT+1.3mm tape (P < .001). CONCLUSIONS: Suture augmentation improves construct biomechanics at time zero following hamstring tendon ACLR. Augmentation with 2.0-mm tape suture improves construct biomechanics compared to 1.3-mm tape suture. CLINICAL RELEVANCE: Independent suture augmentation of a quadrupled SemiT graft improves ACLR construct biomechanics. Outcomes were improved with augmentation using 2.0-mm tape suture compared to 1.3-mm tape suture.

Dual Semitendinosus Allograft Reconstruction of Chronic Achilles Tendon Ruptures: Operative Technique and Outcomes.

BACKGROUND: Dual semitendinosus allograft reconstruction of chronic Achilles tendon ruptures has several potential benefits including superior tensile strength compared with a turndown construct and avoidance of the morbidity and operative time associated with autograft augmentation. We present a series of chronic Achilles tendon ruptures reconstructed with dual semitendinosus allograft. METHODS: We retrospectively reviewed the charts of patients aged 18 years and older who underwent reconstruction of chronic Achilles tendon ruptures using dual semitendinosus allograft. The primary outcome of this study was to evaluate the need for revision surgery. Secondary outcomes included patient-reported outcomes, for which Achilles Tendon Rupture Scores (ATRS) were collected at final follow-up. Nine patients with a mean age of 58.9 (range, 43-75) years met inclusion criteria. RESULTS: Median follow-up was 66 months (range, 27-121 months). One patient (11.1%) required revision reconstruction after sustaining graft failure 9.5 years after her index procedure, and 1 patient reported a poor ATRS score at the 27-month final follow-up despite an intact surgical repair. At final follow-up, no patient required the use of an assistive device for ambulation or a walking boot. The median ATRS at final follow-up was 93 (range, 30-100). DISCUSSION: Good clinical outcomes without rerupture were observed in 7 of 9 patients (77.8%) at short- to midterm follow-up, suggesting that dual semitendinosus allograft reconstruction is a viable option for the reconstruction of chronic Achilles tendon tears. LEVEL OF EVIDENCE: Level IV, case series.

Press-fit fixation in anterior cruciate ligament reconstruction yields low graft failure and revision rates: a systematic review and meta-analysis.

PURPOSE: Press-fit fixation is a hardware-free technique in anterior cruciate ligament reconstruction (ACLR). The purpose of this review was to quantitatively assess the risk profile and outcomes of press-fit fixation and provide an update on its effectiveness compared to more standard fixation techniques of ACLR. METHODS: The electronic databases PUBMED, MEDLINE, and EMBASE were searched on March 26, 2020 for therapeutic randomized controlled trials (RCT) addressing press-fit fixation for primary ACLR. The Grading of Recommendations Assessment, Development and Evaluation tool was used to assess the quality for randomized studies. A meta-analysis with a random-effects model was used to pool applicable outcomes data. RESULTS: A total of six eligible RCTs were included in this review. There were 292 patients (72.9% male) with a mean age of 28.8 ± 3.8 years and a mean follow-up of 81.3 ± 88.3 months that underwent press-fit ACLR on the femoral, tibial or both tunnels. Femoral fixation techniques included press-fit fixation (96.6%) and cross-pin fixation (3.4%). Tibial fixation techniques included press-fit (37.0%), staples (28.1%), interference screws (21.2%) and abarticular post-screws (13.7%). Graft options included bone-patellar tend--bone autografts (73.6%) and semitendinosus and gracilis tendon autograft (26.4%). Significant improvements (p < 0.05) from baseline to follow-up were found for clinical outcomes. Significantly less postoperative bone tunnel enlargement (p < 0.05) was found with tibial press-fit fixation when compared to biodegradable screws. The overall complication rate was 13.3%. There were no significant differences in complication rates [odds ratio = 0.84 (95%CI 0.43-1.66); p = n.s.] (I2 = 0%) between patients undergoing femoral press-fit fixation and femoral metal interference screw fixation. CONCLUSION: The overall graft failure and revision rates with press-fit ACLR were low. There were no significant differences in complication rates between patients undergoing femoral press-fit and femoral metal interference screw fixation. Included studies found that patients undergoing press-fit fixation for ACLR had significant improvements in functional outcome scores postoperatively and had significantly reduced postoperative bone tunnel enlargement compared to patients undergoing bioabsorbable fixation. Thus, early evidence suggests that press-fit fixation appears to be a good option for patients undergoing ACLR. LEVEL OF EVIDENCE: I.

Five-Strand Versus Four-Strand Hamstring Autografts in Anterior Cruciate Ligament Reconstruction-A Prospective Randomized Controlled Study.

PURPOSE: To compare the clinical outcomes of the routine use of 5-strand hamstring grafts (where possible) with those of 4-strand grafts in primary anterior cruciate ligament (ACL) reconstruction. METHODS: A total of 64 patients were enrolled in a prospective randomized controlled study comparing the use of 5-strand and 4-strand semitendinosus-gracilis autografts in single bundle ACL reconstruction (n = 32 in each group). Four participants in each group were lost to follow-up and were excluded from the outcome analysis. The outcomes of 28 patients in the 5-strand group and 28 patients in the 4-strand group were analyzed. The diameters of all grafts were measured intraoperatively. Patients were assessed postoperatively at 2 years with objective assessments (anterior knee laxity using the KT-2000 arthrometer, Lachman test, pivot-shift test, hop test) and patient-reported outcome scores (Lysholm knee score, Knee Injury and Osteoarthritis Outcome Score, International Knee Documentation Committee subjective knee score, SF-36 physical and mental components, Tegner activity scale). Postoperative graft ruptures were also noted. RESULTS: There were improvements in all outcome measures postoperatively regardless of the number of graft strands. When we compared the study and control groups, there were no significant differences in all subjective and objective outcome measures except the Knee Injury and Osteoarthritis Outcome Score symptoms score (5-strand group 93.3 ± 9.2 vs 4-strand group 86.2 ± 14.7, P = .04). The KT-2000 side-to-side difference was 2.79 ± 2.11 mm in the 5-strand group and 2.54 ± 1.75 mm in the 4-strand group (P = .63). The 5-strand study group had 2 graft ruptures at 1 year, whereas the 4-strand control group had one partial graft rupture at 6 months. CONCLUSIONS: At 2-year follow-up, the routine use of the 5-strand hamstring tendon autograft was not superior to that of the quadrupled or 4-strand graft in primary ACL reconstruction. LEVEL OF EVIDENCE: Level I, prospective randomized controlled trial.

Combination of anterior tibial and femoral tunnels makes the signal intensity of antero-medial graft higher in double-bundle anterior cruciate ligament reconstruction.

PURPOSE: To elucidate whether sagittal graft tunnel affects the signal intensity in anatomical ACL reconstruction (ACLR) and to clarify the prevalence of intercondylar roof impingement. It was hypothesized that if the tunnel apertures are located within the anatomical footprint of ACL, tunnel position would not affect the signal intensity. METHODS: A total of 132 patients who underwent anatomical double-bundle ACLR (DB-ACLR) using hamstring autograft were recruited. Tunnel position was determined by the quadrant method on three-dimensional computed tomography; the femoral tunnel position was defined as "high and low" or "deep and shallow", while that of the tibial side was defined as "anterior and posterior" or "medial and lateral". Subjects were divided into three groups according to the tertile of % deep-shallow. The signal intensity was evaluated by the region of interest value of the antero-medial bundle (AMB) and postero-lateral bundle on magnetic resonance imaging at 12 months after reconstruction. Linear regression analysis was conducted to elucidate the relationship between the percentage position of each tunnel and the graft signal intensity. RESULTS: In the shallow tertile group, AMB signal intensity increased in the anterior position of the tibial tunnel (ß = - 0.34; P = 0.025). In the intermediate and deep tertile groups, the tunnel position did not correlate with the signal intensity. CONCLUSIONS: A more anterior tibial tunnel position increases AMB signal intensity in shallower femoral tunnel. Conversely, this correlation is attenuated for deeper femoral tunnels. Surgeons should pay attention to sagittal femoral tunnel position to create a more anterior tibial tunnel position. LEVEL OF EVIDENCE: Level III.

Superior Postoperative Stability and Functional Outcomes With Anteromedial Versus Transtibial Technique of Single-Bundle Autologous Hamstring Anterior Cruciate Ligament Reconstruction: A Meta-analysis of Prospective Randomized Controlled Trials.

PURPOSE: The aim of this meta-analysis was to compare the postoperative stability and functional outcomes of anteromedial (AM)- and transtibial (TT)-based single-bundle hamstring anterior cruciate ligament (ACL) reconstruction techniques. METHODS: A meta-analysis comparing the outcomes of single-bundle hamstring ACL reconstruction using the AM and TT techniques was performed. Prospective randomized controlled trials identified from searches of PubMed, Cochrane, and Embase were included in this review. The outcome measures analyzed included postoperative Lachman test and pivot-shift test results, side-to-side difference, International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner activity score. RESULTS: A total of 7 randomized controlled trials (654 patients) were included in this review. The AM technique, compared with the TT technique, resulted in superior postoperative stability based on the negative Lachman test rate (risk ratio [RR], 1.12; 95% confidence interval [CI], 1.01 to 1.24; P = .03; 95% prediction interval [PI], 0.32 to 3.46), negative pivot-shift test rate (RR, 1.16; 95% CI, 1.06 to 1.28; P = .002; 95% PI, 0.40 to 2.88), and side-to-side difference (weighted mean difference [WMD], -0.32 mm; 95% CI, -0.48 to -0.16; P < .0001; 95% PI, -0.55 to -0.09). Likewise, the AM technique contributed to superior postoperative functional outcomes based on the proportion of IKDC grade A findings (RR, 1.16; 95% CI, 1.02 to 1.32; P = .03; 95% PI, 0.40 to 2.83) and the Lysholm score (WMD, 0.82; 95% CI, 0.23 to 1.41; P = .007; 95% PI, -0.22 to 1.86). However, the AM and TT techniques had comparable subjective IKDC scores (WMD, 0.98; 95% CI, -0.91 to 2.88; P = .31; 95% PI, -3.18 to 5.14) and Tegner activity scores (WMD, 0.32; 95% CI, -0.23 to 0.86; P = .25; 95% PI, -3.84 to 4.48). CONCLUSIONS: The AM method of single-bundle hamstring ACL reconstruction results in superior postoperative stability and functional outcomes compared with the TT method. LEVEL OF EVIDENCE: Level I, systematic review of Level I studies.

Regenerative peripheral nerve interface free muscle graft mass and function.

BACKGROUND: Regenerative peripheral nerve interfaces (RPNIs) transduce neural signals to provide high-fidelity control of neuroprosthetic devices. Traditionally, rat RPNIs are constructed with ~150 mg of free skeletal muscle grafts. It is unknown whether larger free muscle grafts allow RPNIs to transduce greater signal. METHODS: RPNIs were constructed by securing skeletal muscle grafts of various masses (150, 300, 600, or 1200 mg) to the divided peroneal nerve. In the control group, the peroneal nerve was transected without repair. Endpoint assessments were conducted 3 mo postoperatively. RESULTS: Compound muscle action potentials (CMAPs), maximum tetanic isometric force, and specific muscle force were significantly higher for both the 150 and 300 mg RPNI groups compared to the 600 and 1200 mg RPNIs. Larger RPNI muscle groups contained central areas lacking regenerated muscle fibers. CONCLUSIONS: Electrical signaling and tissue viability are optimal in smaller as opposed to larger RPNI constructs in a rat model.

Anterior Cruciate Ligament Reconstruction: A Comparative Clinical Study Between Adjustable and Fixed Length Suspension Devices.

Background: Adjustable-length cortical suspension devices provide technical advantages over fixed-length devices for femoral graft fixation during anterior cruciate ligament (ACL) reconstruction but have shown increased lengthening during cyclic loading in biomechanical studies. The purpose of this study was to prospectively measure graft elongation in vivo along with patient reported outcomes. Methods: Thirty-seven skeletally mature patients diagnosed with anterior cruciate insufficiency who underwent ACL reconstruction using autogenous hamstring graft were included in this study. Thirteen patients received an ACL reconstruction using a fixed loop device (FL) and twenty-four patients were treated with an adjustable-length device (AL) based on surgeon preference. Bilateral knee laxity was measured with a KT1000 Arthrometer before surgery and immediately after surgery with the patient under anesthesia, and at the 6-week, 3-month, and 6-month clinical follow-up appointments. All measurements were made by the same operator with maximum force testing. Differences between the affected knee and the contralateral knee were measured. Patient reported outcomes were collected at 6 and 24 months post-operatively. Results: No difference was found between the FL and AL groups in either knee laxity or patient reported outcomes. Average side-to-side difference at 6 months was 1.8 ± 2.6 mm for the FL group and 1.7 ± 2.4 mm for the AL group (p=.874). One patient in the FL group (7.7%) and two in the AL group (9.5%) had a side to side difference in laxity greater 5 mm. Patient reported outcomes did not differ between groups and no patients underwent revision surgery. Conclusions: The adjustable-length cortical suspension device (AL) did not demonstrate increased laxity as compared to fixed-length devices. There was no difference in patient reported outcomes between the groups.Level of Evidence: IV.

ACL reconstruction using a quadruple semitendinosus graft with cortical fixations gives suitable isokinetic and clinical outcomes after 2 years.

PURPOSE: The objective of this single-center randomized single-blinded trial was to assess the hypothesis that anterior cruciate ligament reconstruction (ACLR) using a four-strand semitendinosus (ST) graft with adjustable femoral and tibial cortical fixation produced good outcomes compared to an ST/gracilis (ST/G) graft with femoral pin transfixation and tibial bioscrew fixation. Follow-up was 2 years. METHODS: Patients older than 16 years who underwent primary isolated ACLR included for 1 year until August 2017 were eligible. The primary outcome measures were the subjective International Knee Documentation Committee (IKDC) score, isokinetic muscle strength recovery, and return to work within 2 years. The study was approved by the ethics committee. RESULTS: Of 66 eligible patients, 60 completed the study and were included, 33 in the 4ST group and 27 in the ST/G group. Mean age was 30.5 ± 8.9 years in the 4ST group and 30.3 ± 8.5 in the ST/G group (n.s.). No significant between-group differences were found for mean postoperative subjective IKDC (4ST group, 80.2 ± 12.5; ST/G group, 83.6 ± 13.6; n.s.), side-to-side percentage deficits in isokinetic hamstring strength (at 60°/s: ST group, 17% ± 16%; ST/G group, 14% ± 11%; n.s.) or quadriceps strength (at 60°/s: ST group, 14% ± 12%; ST/G group, 19% ± 17%; n.s.), return to work, pain during physical activities, side-to-side differential laxity, balance, loss of flexion/extension, or surgical complications. CONCLUSION: This trial demonstrates that functional outcomes after 4ST for ACLR with cortical fixations could be as good, although not better, than those obtained using ST/G. The 4ST technique spares the gracilis tendon, which thus preserves the medial sided muscle and thereby could improve function and limit donor-side morbidity. LEVEL OF EVIDENCE: Level I.

Comparative Study of Spring Ligament Reconstructions Using Either Hamstring Allograft or Synthetic Ligament Augmentation.

BACKGROUND: Idiopathic flatfeet are usually caused by attenuation of the medial soft tissues rather than a lateral osseous deficiency. Debate continues on whether spring ligament attenuation or posterior tibial tendon (PTT) dysfunction is the initial driver for the deformity. Our comparative prospective study aimed to quantify the radiological and clinical outcomes of 2 techniques for spring ligament reconstruction using a hamstring graft or a synthetic ligament. METHODS: Seventeen spring ligament reconstructions (SLRs) were performed in 17 patients using synthetic ligament augmentation and 16 SLRs were performed using hamstring allograft in 13 patients. Additional procedures such as gastrocnemius recession, PTT advancement, flexor digitorum longus transfer, and calcaneal osteotomy were performed as required. A minimum of 12 months of follow-up was available for all cases. Radiographic analysis was performed with standardized parameters. RESULTS: Following SLR with synthetic ligament augmentation, all radiological parameters significantly improved (P < .05). Hamstring allograft SLR also demonstrated significantly improved radiographic parameters in all but Meary's line at final follow-up. At 12 months, patient outcome scores were significantly better in the synthetic ligament group. CONCLUSION: Reconstruction of the spring ligament using either hamstring allograft or synthetic ligament augmentation provided significant improvements in radiological alignment; however, superior patient-reported outcomes were found in the synthetic ligament augmentation group. LEVELS OF EVIDENCE: Level III, retrospective cohort study.

Effects of Autograft Types on Muscle Strength and Functional Capacity in Patients Having Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial.

BACKGROUND: The effects of different autograft types for anterior cruciate ligament reconstruction (ACL-R) on muscle function are sparsely investigated in randomized controlled trials. Our aim was to investigate the effects of quadriceps tendon autograft (QTB) vs. semitendinosus-gracilis autograft (StG) on thigh muscle strength and functional capacity, and a patient-reported outcome 1 year after ACL-R, and to compare the results to healthy controls. METHODS: ACL-R patients (n = 100) and matched controls (CON, n = 50) were recruited, with patients being randomly assigned to QTB (n = 50) or StG (n = 50) ACL-R. One year after ACL-R, bilateral knee extensor (KE) and flexor (KF) muscle strength (isometric, dynamic, explosive, limb symmetry index [LSI], hamstring:quadriceps ratio [HQ ratio]) were assessed by isokinetic dynamometry, along with functional capacity (single leg hop distance [SHD]) and a patient-reported outcome (International Knee Documentation Committee [IKDC] score). RESULTS: KE muscle strength of the operated leg was lower (9-11%) in QTB vs. StG as was KE LSI, while KF muscle strength was lower (12-17%) in StG vs. QTB as was KF LSI. HQ ratios were lower in StG vs. QTB. Compared with the controls, KE and KF muscle strength were lower in StG (10-22%), while KE muscle strength only was lower in QTB (16-25%). Muscle strength in the StG, QTB, and CON groups was identical in the non-operated leg. While SHD and IKDC did not differ between StG and QTB, SHD in both StG and QTB was lower than CON. The IKDC scores improved significantly 1 year following ACL-R for both graft types. CONCLUSION: One year after ACL-R, muscle strength is affected by autograft type, with StG leading to impairments of KE and KF muscle strength, while QTB results in more pronounced impairments of KE only. Functional capacity and patient-reported outcome were unaffected by autograft type, with the former showing impairment compared to healthy controls. CLINICAL TRIALS REGISTRATION NUMBER: NCT02173483.

Joint laxity and graft compliance increase during the first year following ACL reconstruction with short hamstring tendon grafts.

PURPOSE: Evaluating joint laxity and graft compliance after ACL surgery may be used to quantify biomechanical graft properties during the ligamentization process. This study aimed to analyse the evolvement of joint laxity and graft compliance of short hamstring tendon grafts after ACL reconstruction (ACLR). METHODS: Forty-seven patients that underwent ACLR were retrospectively enrolled. Joint laxity was quantified with a GNRB® arthrometer before surgery, then at 15 days, at 1/3/6/9 months (M1-M9), at 1 year postoperatively and then again at the last mean follow-up (FU) of 14.7 ± 3.0 months. The side-to-side laxity difference (ΔL in mm) was measured at 30 and 60 N at every FU, additionally at 90 N from M3 on and at 134 N from M6 on. The side-to-side compliance difference (ΔC in µm/N) was calculated for each graft. RESULTS: Mean ΔL and ΔC decreased significantly between preoperative and M1 for all applied forces (at 30 N, ΔL: 0.8 mm, p < 0.0001; ΔC: 25.9 µm/N, p < 0.001). Between M1 and M9, ΔL increased significantly at 30 N (p = 0.02) and 60 N (p < 0.001), while ΔC increased by 15.2 µm/N at 30 N (p = 0.003) and 14.9 µm/N at 60 N (p = 0.001). Between M9 and the last FU, there were no significant differences for ΔL and ΔC. CONCLUSION: Joint laxity and graft compliance evolve during the first postoperative year with a phase between the first and ninth postoperative month of relative weakness. According to the established evolvement profile, return to pivoting or contact sports should be considered only after stabilization of joint laxity and graft compliance. LEVEL OF EVIDENCE: Retrospective cohort study, Level III.

Good outcomes at mid-term following the reconstruction of chronic Achilles tendon rupture with semitendinosus allograft.

PURPOSE: Chronic Achilles tendon rupture is commonly treated surgically, yet there are limited available data on tendon allografts for Achilles tendon reconstruction. The purpose of this study was to evaluate the patient-reported outcomes of chronic Achilles tendon rupture reconstructed with semitendinosus allograft. METHODS: A total of 34 patients (30 males and 4 females, average age 36.1 ± 6.8 years ranging from 25 to 50 years) who underwent Achilles tendon reconstruction with semitendinosus allograft from 2011 to 2015 were identified for this retrospective study. The American Orthopedic Foot and Ankle Society (AOFAS) score, Victorian Institute of Sports Assessment-Achilles (VISA-A) score, Achilles tendon total rupture score (ATRS), and Tegner score were evaluated preoperatively and at final follow-up. RESULTS: A total of 33 patients (97.1%) were followed up for a median time of 53 (range 24-80) months. The median AOFAS score increased from 50 (5-75) to 100 (86-100), the median VISA-A score increased from 23 (5-59) to 94 (52-100), the median ATRS score increased from 22.5 (6-67) to 99 (84-100), and the median Tegner score increased from 1 (0-3) to 4 (3-9). CONCLUSIONS: Reconstruction of chronic-ruptured Achilles tendon with semitendinosus allograft offers satisfactory patient-reported results with low risk of re-rupture and complications. This technique could be considered an effective alternative for chronic ruptures of the Achilles tendon. LEVEL OF EVIDENCE: Case series, Level IV.

Quadriceps Torque, Peak Variability and Strength Endurance in Patients after Anterior Cruciate Ligament Reconstruction: Impact of Local Muscle Fatigue.

We tested if ACL-reconstructed participants show a decreased quadriceps torque, a lower muscle endurance capacity and a higher peak torque variability compared to unimpaired control participants prior to and following local muscle fatigue. Participants (n = 19, 10 women; 25 ± 5yrs.) with unilateral hamstrings autograft ACL-reconstruction and a matched unimpaired control group were recruited. Participants performed two maximal isometric voluntary force (MIVF) contractions of the knee extensors. In between, standardized local muscle fatigue was induced. ACL-reconstructed knees display a lower peak torque of the knee extensors in comparison to the contralateral limb (3.2 ± .3Nm/kg vs. 3.5 ± .3 Nm/kg). Peak torque variability and fatigue resistance were not affected by local muscle fatigue (p > .05). Participants with ACL-reconstructed knees show a persistent quadriceps muscle dysfunction. This dysfunction and lower limb side asymmetries might be risk factors for ACL re-ruptures.

No effect of graft size or body mass index on risk of revision after ACL reconstruction using hamstrings autograft.

PURPOSE: The current study investigated the distribution of hamstrings graft size and body mass index and any potential effect on the risk of revision surgery in a large prospective cohort of patients undergoing ACL reconstruction. More specifically, the aim of the study was to investigate whether larger graft size or smaller BMI would decrease the risk of revision after ACL reconstruction. METHODS: A total of 4029 patients, prospectively registered in the Norwegian Knee Ligament Registry, were included in the study. Univariate Kaplan-Meier survival analyses (with log-rank tests) and the Cox proportional hazard (PH) regression model were applied to compare risk of revision between groups of patients. Mutual adjustment for gender, age, activity at the time of injury and fixation method of the graft was performed. RESULTS: Graft sizes spanned from 5.5 to 11.0 mm and the median of 8.0 mm was reported in 42% of patients in the cohort. BMI was reported from 15 to 57 with a median of 25. 46% of patients were classified as overweight (WHO standards), while 23% of patients were obese. At a median of 2.5 years after surgery, 150 patients had undergone revision surgery. Although certain effects were seen in the unadjusted analyses, neither graft size (diameter) nor patient BMI did affect the risk of undergoing revision surgery in the adjusted analyses. CONCLUSIONS: Graft size and BMI was not found to be independent risk factors for undergoing ACL revision surgery. In contrast to other studies, graft size of 8 mm or larger did not have a better outcome than smaller graft sizes. A relatively large group of overweight patients undergoing ACL surgery reflects the general increase in weight seen in Western societies. Although the current study differs from previous findings, it might indicate that graft diameter is less important than previously stated. LEVEL OF EVIDENCE: Cohort study, II.

Minimally invasive reconstruction technique for chronic Achilles tendon tears allows rapid return to walking and leads to good functional recovery.

PURPOSE: Chronic Achilles tendon tears, including chronic ruptures with end gap over 6 cm making end-to-end suturing impossible, can be treated with autologous hamstring graft reconstruction. The primary goal of this study was to present the biomechanical and long-term clinical results of recently developed minimally invasive Achilles tendon reconstruction technique. METHODS: Minimally invasive Achilles tendon reconstruction was applied to 8 foot and ankle cadaveric specimens as well as 18 patients with chronic Achilles tendon tears. Repaired cadavers were subjected to the biomechanical testing using a cyclic loading protocol. Patients with reconstructed Achilles tendon were subjected to the clinical, functional and isokinetic tests at 12 months after the treatment. RESULTS: All of tested Achilles cadaveric specimens survived 2 loading blocks (250 cycles of 10-100 N load followed by additional 250 cycles of 10-200 N load). With three specimens, it was possible to perform the third cyclic loading block with 20-300 N load and two specimens survived the fourth block with 20-400 N load. Therefore, a mean number of 838 cycles (±178) within the range of 509-1000 was recorded. Two specimens which survived all 1000 cycles were pulled to failure at 25 mm/s rate. The results obtained in the load to failure testing were as follows: 398 N and 608 N of maximum load. The results of functional heel rise endurance test and single leg hop for distance test indicated a decrease in the endurance and strength of the injured limb. However, the results of the weight-bearing lunge tests indicated no tendency for elongation of the Achilles tendon. A comparative analysis of the isokinetic test results for the non-injured and injured limb was revealed no statistically significant differences for every isokinetic test (n. s.), with significant difference for isometric strength parameters (p = 0.0006). CONCLUSIONS: The results of the biomechanical tests as well as 1-year extensive functional, clinical and isokinetic results of the minimally invasive technique for chronic Achilles tendon tears are encouraging. Patients returned to their normal physical activity, including sport pre-injury level in most cases. LEVEL OF EVIDENCE: III.

Longitudinal Quadriceps Strength Recovery After Anterior Cruciate Ligament Reconstruction With Hamstring Autograft: Patients Stratified by Preoperative Quadriceps Strength Deficit.

CONTEXT: Some studies have discussed postoperative quadriceps strength recovery after anterior cruciate ligament reconstruction (ACLR). However, the effect of preoperative quadriceps strength deficit on longitudinal postoperative quadriceps strength recovery after ACLR with hamstring autograft is unknown. OBJECTIVE: To reveal the longitudinal postoperative quadriceps strength recovery after ACLR with hamstring autograft among patient groups stratified by preoperative quadriceps strength deficit. DESIGN: Retrospective cohort study. SETTING: Single center. PATIENTS: In total, 420 patients (222 men and 218 women; age at the time of surgery 23.1 [8.9] y) who underwent ipsilateral ACLR with hamstring autograft and completed knee function tests preoperatively and 3, 6, and 12 months postoperatively were included in this study. INTERVENTION: The authors measured quadriceps strength at 60°/s, tested 1-leg hop performance (distance and anxiety), and calculated the quadriceps strength index (QSI) and limb symmetry index for 1-leg hop distance. Patients were divided into the following 4 groups according to their preoperative QSI: >80% (Excellent group), 80% to 60% (Good group), 60% to 40% (Moderate group), and ≤40% (Poor group). MAIN OUTCOME MEASURES: Postoperative QSI at 3, 6, and 12 months and 1-leg hop performance at 12 months after the surgery. RESULTS: The Excellent group had the highest postoperative QSI at all periods. Based on the 1-leg hop performance, the Poor group had the lowest limb symmetry index and significantly greater anxiety during jump performance in comparison with the Excellent and Good groups. CONCLUSION: The present study shows a longitudinal recovery process and the average postoperative quadriceps strength after ACLR with hamstring autograft in patient groups stratified by preoperative QSI. The results indicate that the difference in preoperative QSI affects not only the longitudinal postoperative QSI recovery but also high-level 1-leg hop performance after ACLR using hamstring autograft.

Quadriceps tendon autograft ACL reconstructed subjects overshoot target knee extension angle during active proprioception testing.

PURPOSE: To compare the active joint position sense (JPS), muscle strength, and knee functions in individuals who had anterior cruciate ligament (ACL) reconstruction with quadriceps tendon autograft, hamstring tendon autograft, tibialis anterior allograft and healthy individuals. It was hypothesized that when compared to an age and gender-matched healthy control group, subjects who were post-ACL reconstruction would display impaired active joint position sense, knee extensor and flexor strength symmetry and knee function at 1 year post-surgery. A secondary hypothesis was that differences would exist between the quadriceps tendon autograft, hamstring tendon autograft and tibialis anterior allograft groups. METHODS: Sixty-seven patients with ACL reconstruction and 20 healthy individuals were included. Active JPS reproduction was measured at 15°, 45° and 75° of knee flexion. International Knee Documentation Committee (IKDC) subjective score and one-leg hop test were used to assess the functional status of the patients. RESULTS: The JPS detection was different at the 15° target angle between groups (F3.86 = 24.56, p < 0.001). A significantly higher proportion of quadriceps tendon autograft group patients failed to identify the 15° active JPS assessment position compared to the other groups (p < 0.0001). The quadriceps index was lower in patients compared to healthy individuals (p < 0.001), while the hamstring index was similar (n.s.). The knee functional outcomes were similar between ACL reconstructed groups and healthy controls (n.s.). CONCLUSION: Knee proprioception deficits and impaired muscle strength were evident among patients at a mean 13.5 months post-ACL reconstruction compared with healthy controls. Patients who underwent ACL reconstruction using a quadriceps tendon autograft may be more likely to actively over-estimate knee position near terminal extension. Physiotherapists may need to focus greater attention on terminal knee extension proprioceptive awareness among this patient group. LEVEL OF EVIDENCE: III.