Aims. To verify whether secretory leucocyte protease inhibitor (SLPI) can promote early tendon-to-bone healing after anterior cruciate ligament (ACL) reconstruction. Methods. In vitro: the mobility of the rat bone mesenchymal stem cells (BMSCs) treated with SLPI was evaluated by scratch assay. Then the expression levels of osteogenic differentiation-related genes were analyzed by real-time quantitative PCR (qPCR) to determine the osteogenic effect of SLPI on BMSCs. In vivo: a rat model of ACL reconstruction was used to verify the effect of SLPI on tendon-to-bone healing. All the animals of the SLPI group and the negative control (NC) group were euthanized for histological evaluation, micro-CT scanning, and biomechanical testing. Results. SLPI improved the migration ability of BMSCs and upregulated the expression of genes related to osteogenic differentiation of BMSCs in vitro. In vivo, the SLPI group had higher histological scores at the tendon-bone interface by histological evaluation. Micro-CT showed more new bone formation and bone ingrowth around the grafted tendon in the SLPI group. Evaluation of the healing strength of the tendon-bone connection showed that the SLPI group had a higher maximum failure force and stiffness. Conclusion. SLPI can effectively promote early tendon-to-bone healing after ACL reconstruction via enhancing the migration and osteogenic differentiation of BMSCs. Cite this article: Bone Joint Res 2022;11(7):503–512

Aims. The aim of this study was to compare the preinjury functional scores with the postinjury preoperative score and postoperative outcome scores following anterior cruciate ligament (ACL) reconstruction surgery (ACLR). Methods. We performed a prospective study on patients who underwent primary ACLR by a single surgeon at a single centre between October 2010 and January 2018. Preoperative preinjury scores were collected at time of first assessment after the index injury. Preoperative (pre- and post-injury), one-year, and two-year postoperative functional outcomes were assessed by using the Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm Knee Score, and Tegner Activity Scale. Results. We enrolled 308 males and 263 females of mean age 27 years (19 to 46). The mean preinjury and preoperative post-injury Lysholm Knee Scores were 94 (73 to 100) and 63 (25 to 85), respectively, while the respective mean scores at one and two years postoperatively were 84 (71 to 100) and 89 (71 to 100; p < 0.001). The mean Tegner preinjury and preoperative post-injury scores were 7 (3 to 9) and 3 (0 to 6), respectively, while the respective mean scores at one and two years postoperatively were 6 (1 to 8) and 6 (1 to 9) (p < 0.001). The mean KOOS scores at preinjury versus two years postoperatively were: symptoms (96 vs 84); pain (94 vs 87); activities of daily living (97 vs 91), sports and recreation function (84 vs 71), and quality of life (82 vs 69), respectively (p < 0.001). Conclusion. Functional scores improved following ACLR surgery at two years in comparison to preoperative post-injury scores. However, at two-year follow-up, the majority of patients failed to achieve their preinjury scores. The evaluation of ACLR outcomes needs to consider the preinjury scores rather than the immediate preoperative score that is usually collected. Cite this article: Bone Jt Open 2023;4(1):46–52

Aims. Patient dissatisfaction following primary total knee arthroplasty (TKA) with manual jig-based instruments has been reported to be as high as 30%. Robotic-assisted total knee arthroplasty (RA-TKA) has been increasingly used in an effort to improve patient outcomes, however there is a paucity of literature examining patient satisfaction after RA-TKA. This study aims to identify the incidence of patients who were not satisfied following RA-TKA and to determine factors associated with higher levels of dissatisfaction. Methods. This was a retrospective review of 674 patients who underwent primary TKA between October 2016 and September 2020 with a minimum two-year follow-up. A five-point Likert satisfaction score was used to place patients into two groups: Group A were those who were very dissatisfied, dissatisfied, or neutral (Likert score 1 to 3) and Group B were those who were satisfied or very satisfied (Likert score 4 to 5). Patient demographic data, as well as preoperative and postoperative patient-reported outcome measures, were compared between groups. Results. Overall, 45 patients (6.7%) were in Group A and 629 (93.3%) were in Group B. Group A (vs Group B) had a higher proportion of male sex (p = 0.008), preoperative chronic opioid use (p < 0.001), preoperative psychotropic medication use (p = 0.01), prior anterior cruciate ligament (ACL) reconstruction (p < 0.001), and preoperative symptomatic lumbar spine disease (p = 0.004). Group A was also younger (p = 0.023). Multivariate analysis revealed preoperative opioid use (p = 0.012), prior ACL reconstruction (p = 0.038), male sex (p = 0.006), and preoperative psychotropic medication use (p = 0.001) as independent predictive factors of patient dissatisfaction. Conclusion. The use of RA-TKA demonstrated a high rate of patient satisfaction (629 of 674, 93.3%). Demographics for patients not satisfied following RA-TKA included: male sex, chronic opioid use, chronic psychotropic medication use, and prior ACL reconstruction. Patients in these groups should be identified preoperatively and educated on realistic expectations given their comorbid conditions. Cite this article: Bone Jt Open 2024;5(9):758–765

Cite this article: Bone Joint J 2023;105-B(11):1133–1134.

Aims

The effects of remnant preservation on the anterior cruciate ligament (ACL) and its relationship with the tendon graft remain unclear. We hypothesized that the co-culture of remnant cells and bone marrow stromal cells (BMSCs) decreases apoptosis and enhances the activity of the hamstring tendons and tenocytes, thus aiding ACL reconstruction.

Aims

The best surgical strategy for the management of displaced bucket-handle (BH) meniscal tears in an anterior cruciate ligament (ACL)-deficient knee is unclear. Combining meniscal repair with ACL reconstruction (ACLR) is thought to improve meniscal healing rates; however, patients with displaced BH meniscal tears may lack extension. This leads some to advocate staged surgery to avoid postoperative stiffness and loss of range of motion (ROM) following ACLR.

Aims

There is limited information on outcomes of revision ACL reconstruction (rACLR) in soccer (association football) athletes, particularly on return to sport and the rate of additional knee surgery. The purpose of this study was to report return to soccer after rACLR, and to test the hypothesis that patient sex and graft choice are associated with return to play and the likelihood of future knee surgery in soccer players undergoing rACLR.

Aims

MRI has been suggested as an objective method of assessing anterior crucate ligament (ACL) graft “ligamentization” after reconstruction. It has been proposed that the MRI appearances could be used as an indicator of graft maturity and used as part of a return-to-sport assessment. The aim of this study was to evaluate the correlation between MRI graft signal and postoperative functional scores, anterior knee laxity, and patient age at operation.

Aims. To evaluate graft healing of decellularized porcine superflexor tendon (pSFT) xenograft in an ovine anterior cruciate ligament (ACL) reconstruction model using two femoral fixation devices. Also, to determine if pSFT allows functional recovery of gait as compared with the preoperative measurements. Methods. A total of 12 sheep underwent unilateral single-bundle ACL reconstruction using pSFT. Two femoral fixation devices were investigated: Group 1 (n = 6) used cortical suspensory fixation (Endobutton CL) and Group 2 (n = 6) used cross-pin fixation (Stratis ST). A soft screw was used for tibial fixation. Functional recovery was quantified using force plate analysis at weeks 5, 8, and 11. The sheep were euthanized after 12 weeks and comprehensive histological analysis characterized graft healing at the graft-bone interface and the intra-articular graft (ligamentization). Results. The pSFT remodelled into a ligament-like structure and no adverse inflammatory reaction was seen. The ground reaction force in the operated leg of the Endobutton group was higher at 11 weeks (p < 0.05). An indirect insertion was seen at the graft-bone interface characterized by Sharpey-like fibres. Qualitative differences in tendon remodelling were seen between the two groups, with greater crimp-like organization and more aligned collagen fibres seen with Endobutton fixation. One graft rupture occurred in the cross-pin group, which histologically showed low collagen organization. Conclusion. Decellularized pSFT xenograft remodels into a ligament-like structure after 12 weeks and regenerates an indirect-type insertion with Sharpey-like fibres. No adverse inflammatory reaction was observed. Cortical suspensory femoral fixation was associated with more enhanced graft remodelling and earlier functional recovery when compared with the stiffer cross-pin fixation

Aims. Adenosine, lidocaine, and Mg. 2+. (ALM) therapy exerts differential immuno-inflammatory responses in males and females early after anterior cruciate ligament (ACL) reconstruction (ACLR). Our aim was to investigate sex-specific effects of ALM therapy on joint tissue repair and recovery 28 days after surgery. Methods. Male (n = 21) and female (n = 21) adult Sprague-Dawley rats were randomly divided into ALM or Saline control treatment groups. Three days after ACL rupture, animals underwent ACLR. An ALM or saline intravenous infusion was commenced prior to skin incision, and continued for one hour. An intra-articular bolus of ALM or saline was also administered prior to skin closure. Animals were monitored to 28 days, and joint function, pain, inflammatory markers, histopathology, and tissue repair markers were assessed. Results. Despite comparable knee function, ALM-treated males had reduced systemic inflammation, synovial fluid angiogenic and pro-inflammatory mediators, synovitis, and fat pad fibrotic changes, compared to controls. Within the ACL graft, ALM-treated males had increased expression of tissue repair markers, decreased inflammation, increased collagen organization, and improved graft-bone healing. In contrast to males, females had no evidence of persistent systemic inflammation. Compared to controls, ALM-treated females had improved knee extension, gait biomechanics, and elevated synovial macrophage inflammatory protein-1 alpha (MIP-1α). Within the ACL graft, ALM-treated females had decreased inflammation, increased collagen organization, and improved graft-bone healing. In articular cartilage of ALM-treated animals, matrix metalloproteinase (MMP)-13 expression was blunted in males, while in females repair markers were increased. Conclusion. At 28 days, ALM therapy reduces inflammation, augments tissue repair patterns, and improves joint function in a sex-specific manner. The study supports transition to human safety trials. Cite this article: Bone Joint Res 2024;13(6):279–293

The June 2015 Knee Roundup360 looks at: Cruciate substituting versus retaining knee replacement; What’s behind the psychology of anterior cruciate ligament (ACL) reconstruction?; Is there a difference in total knee arthroplasty risk of revision in highly crosslinked versus conventional polyethylene?; Unicompartmental knee arthroplasty: is age the missing variable?; Satisfaction rates following total knee arthroplasty; Is knee alignment dynamic?; Unicompartmental knee arthroplasty: cemented or cementless?; Can revision knee services pay?

Aims. The aim of this study was to investigate the incidence, risk factors, and outcome of venous thromboembolism (VTE) following anterior cruciate ligament (ACL) reconstruction in a nationwide cohort. Patients and Methods. All ACL reconstructions, primary and revision, that were recorded in the Swedish Knee Ligament Register (SKLR) between 2006 and 2013 were linked with data from the Swedish National Board of Health and Welfare. The incidence of VTE was determined by entries between the day of surgery until 90 days postoperatively based on diagnosis codes and the prescription of anticoagulants. Risk factors, outcome, and the use of thromboprophylaxis were analyzed. Descriptive statistics with multivariate analysis were used to describe the findings. Results. The cohort consisted of 26 014 primary and revision ACL reconstructions. There were 89 deep venous thromboses (DVTs) and 12 pulmonary emboli (PEs) with a total of 95 VTEs (0.4 %). Six patients with a PE had a simultaneous DVT. The only independent risk factor for VTE was age greater than or equal to 40 years (odds ratio 2.31, 95% confidence interval 1.45 to 3.70; p < 0.001). Thromboprophylaxis was prescribed to 9461 patients (36%) and was equally distributed between those with and those without a VTE (37.9% vs 36.4%). All patient-reported outcome measures (PROMs) one and two years postoperatively were significantly lower in those with VTE. Conclusion. The incidence of VTE following ACL reconstruction is 0.4%, and the only significant risk factor is age. Patients with VTE had worse postoperative clinical outcome than patients without VTE. We recommend against the routine use of thromboprophylaxis, but it should be considered in older patients

Objectives. To compare the effect of femoral bone tunnel configuration on tendon-bone healing in an anterior cruciate ligament (ACL) reconstruction animal model. Methods. Anterior cruciate ligament reconstruction using the plantaris tendon as graft material was performed on both knees of 24 rabbits (48 knees) to mimic ACL reconstruction by two different suspensory fixation devices for graft fixation. For the adjustable fixation device model (Socket group; group S), a 5 mm deep socket was created in the lateral femoral condyle (LFC) of the right knee. For the fixed-loop model (Tunnel group; group T), a femoral tunnel penetrating the LFC was created in the left knee. Animals were sacrificed at four and eight weeks after surgery for histological evaluation and biomechanical testing. Results. Histologically, both groups showed a mixture of direct and indirect healing patterns at four weeks, whereas only indirect healing patterns were observed in both groups at eight weeks. No significant histological differences were seen between the two groups at four and eight weeks in the roof zone (four weeks, S: mean 4.8 . sd. 1.7, T: mean 4.5 . sd. 0.5, p = 0.14; eight weeks, S: mean 5.8 . sd. 0.8, T: mean 4.8 . sd. 1.8, p = 0.88, Mann-Whitney U test) or side zone (four weeks, S: mean 5.0 . sd. 1.2, T: mean 4.8 . sd. 0.4, p = 0.43; eight weeks, S: mean 5.3 . sd. 0.8,T: mean 5.5 . sd. 0.8, p = 0.61, Mann-Whitney U test) . Similarly, no significant difference was seen in the maximum failure load between group S and group T at four (15.6 . sd. 9.0N and 13.1 . sd. 5.6N) or eight weeks (12.6 . sd. 3.6N and 17.1 . sd. 6.4N, respectively). Conclusion. Regardless of bone tunnel configuration, tendon-bone healing after ACL reconstruction primarily occurred through indirect healing. No significant histological or mechanical differences were observed between adjustable and fixed-loop femoral cortical suspension methods. Cite this article: Y. Sato, R. Akagi, Y. Akatsu, Y. Matsuura, S. Takahashi, S. Yamaguchi, T. Enomoto, R. Nakagawa, H. Hoshi, T. Sasaki, S. Kimura, Y. Ogawa, A. Sadamasu, S. Ohtori, T. Sasho. The effect of femoral bone tunnel configuration on tendon-bone healing in an anterior cruciate ligament reconstruction: An animal study. Bone Joint Res 2018;7:327–335. DOI: 10.1302/2046-3758.75.BJR-2017-0238.R2

The use of platelet-rich plasma (PRP) as an adjuvant to tissue repair is gaining favour in orthopaedic surgery. Tunnel widening after anterior cruciate ligament (ACL) reconstruction is a recognised phenomenon that could compromise revision surgery. The purpose of this study was to determine whether PRP might prevent tunnel widening in ACL reconstruction. Patients undergoing ACL reconstruction using a hamstring graft were randomly allocated either to have PRP introduced into the tunnels peri-operatively or not. CT scanning of the knees was carried out on the day after surgery and at three months post-operatively and the width of the tunnels was measured. Patients were also evaluated clinically at three months, when laxity was also measured. Each group comprised 25 patients, and at three months post-operatively all were pain-free with stable knees, a negative Lachman test and a good range of movement. Arthrometric results had improved significantly in both groups (p < 0.001). Despite slightly less tunnel widening in the PRP group, there was no significant difference between the groups at the femoral opening or the mid-tunnel (p = 0.370 and p = 0.363, respectively) nor at the tibial opening or mid-tunnel (p = 0.333 and p = 0.177, respectively). We conclude that PRP has no significant effect in preventing tunnel widening after ACL reconstruction. Cite this article: Bone Joint J 2013;95-B:65–9

Between 1993 and 1994, 891 patients underwent primary anterior cruciate ligament (ACL) reconstruction. A total of 48 patients had undergone bilateral ACL reconstruction and 42 were available for review. These patients were matched to a unilateral ACL reconstruction control group for gender, age, sport of primary injury, meniscal status and graft type. At 15-year follow-up a telephone interview with patients in both groups was performed. The incidence of further ACL injury was identified through structured questions and the two groups were compared for the variables of graft rupture or further ACL injury, family history of ACL injury, International Knee Documentation Committee (IKDC) subjective score and activity level. There were 28 male and 14 female patients with a mean age of 25 years (13 to 42) at the time of first ACL injury. Subsequent further ACL injury was identified in ten patients (24%) in the bilateral ACL reconstruction study group and in nine patients (21%) in the unilateral ACL reconstruction control group (p = 0.794). The mean time from bilateral ACL reconstruction to further ACL injury was 54 months (6 to 103). There was no significant difference between the bilateral ACL reconstruction study group and the matched unilateral ACL reconstruction control group in incidence of further ACL injury (p = 0.794), family history of ACL injury (p = 0.595), IKDC activity level (p = 0.514), or IKDC subjective score (p = 0.824). After bilateral ACL reconstruction the incidence of graft rupture and subjective outcomes were equivalent to that after unilateral ACL reconstructions. Cite this article: Bone Joint J 2013;95-B:798–802

We report the clinical outcome and findings at second-look arthroscopy of 216 patients (mean age 25 years (11 to 58)) who underwent anterior cruciate ligament (ACL) reconstruction or augmentation. There were 73 single-bundle ACL augmentations (44 female, 29 male), 82 double-bundle ACL reconstructions (35 female, 47 male), and 61 single-bundle ACL reconstructions (34 female, 27 male). In 94 of the 216 patients, proprioceptive function of the knee was evaluated before and 12 months after surgery using the threshold to detect passive motion test. Second-look arthroscopy showed significantly better synovial coverage of the graft in the augmentation group (good: 60 (82%), fair: 10 (14%), poor: 3 (4%)) than in the other groups (p = 0.039). The mean side-to-side difference measured with a KT-2000 arthrometer was 0.4 mm (-3.3 to 2.9) in the augmentation group, 0.9 mm (-3.2 to 3.5) in the double-bundle group, and 1.3 mm (-2.7 to 3.9) in the single-bundle group: the result differed significantly between the augmentation and single-bundle groups (p = 0 .013). No significant difference in the Lysholm score or pivot-shift test was seen between the three groups (p = 0.09 and 0.65, respectively). In patients with good synovial coverage, three of the four measurements used revealed significant improvement in proprioceptive function (p = 0.177, 0.020, 0.034, and 0.026). We conclude that ACL augmentation is a reasonable treatment option for patients with favourable ACL remnants. Cite this article: Bone Joint J 2014;96-B:1325–32