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. Methods. The ACL remnant, bone marrow, and hamstring tendons were surgically harvested from rabbits. The apoptosis rate, cell proliferation, and expression of types I and III collagen, transforming growth factor-β (TGF-β), vascular endothelial growth factor (VEGF), and tenogenic genes (scleraxis (SCX), tenascin C (TNC), and tenomodulin (TNMD)) of the hamstring tendons were compared between the co-culture medium (ACL remnant cells (ACLRCs) and BMSCs co-culture) and control medium (BMSCs-only culture). We also evaluated the apoptosis, cell proliferation, migration, and gene expression of hamstring tenocytes with exposure to co-culture and control media. Results. Compared to BMSCs-only culture medium, the co-culture medium showed substantially decreased early and late apoptosis rates, attenuation of intrinsic and extrinsic apoptotic pathways, and enhanced proliferation of the hamstring tendons and tenocytes. In addition, the expression of collagen synthesis, TGF-β, VEGF, and tenogenic genes in the hamstring tendons and tenocytes significantly increased in the co-culture medium compared to that in the control medium. Conclusion. In the presence of ACLRCs and BMSCs, the hamstring tendons and tenocytes significantly attenuated apoptosis and enhanced the expression of collagen synthesis, TGF-β, VEGF, and tenogenic genes. This in vitro study suggests that the ACLRCs mixed with BMSCs could aid regeneration of the hamstring tendon graft during ACL reconstruction. Cite this article: Bone Joint Res 2023;12(1):9–21

Aims. To test the hypothesis that reseeded anterior cruciate ligament (ACL)-derived cells have a better ability to survive and integrate into tendon extracellular matrix (ECM) and accelerate the ligamentization process, compared to adipose-derived mesenchymal stem cells (ADMSCs). Methods. Acellularized tibialis allograft tendons were used. Tendons were randomly reseeded with ACL-derived cells or ADMSCs. ACL-derived cells were harvested and isolated from remnants of ruptured ACLs during reconstruction surgery and cultured at passage three. Cell suspensions (200 µl) containing 2 × 10. 6. ACL-derived cells or ADMSCs were prepared for the purpose of reseeding. At days 1, 3, and 7 post-reseeding, graft composites were assessed for repopulation with histological and immunohistochemical analysis. Matrix protein contents and gene expression levels were analyzed. Results. In the graft reseeded with ACL-derived cells, a large number of elongated cells that integrated into the matrix were evident at day 3 and day 7. However, in the graft reseeded with ADMSCs, only a small number of elongated cells were found integrated into the matrix. Immunofluorescence for Ki-67 and type I collagen confirmed the pronounced production of type I collagen by Ki-67-positive ACL-derived cells integrated into the ECM. A messenger RNA (mRNA) expression assay demonstrated significantly higher gene expression levels of types I (p = 0.013) and III (p = 0.050) collagen in the composites reseeded with ACL-derived cells than ADMSCs. Conclusion. ACL-derived cells, when reseeded to acellularized tendon graft, demonstrated earlier better survival and integration in the tendon ECM and resulted in higher gene expression levels of collagen, which may be essential to the normal ligamentization process compared to ADMSCs. Cite this article: Bone Joint Res 2022;11(11):777–786

Aims. The traditional transosseus flexor hallucis longus (FHL) tendon transfer for patients with Achilles tendinopathy requires two incisions to harvest a long tendon graft. The use of a bio-tenodesis screw enables a short graft to be used and is less invasive, but lacks supporting evidence about its biomechanical behaviour. We aimed, in this study, to compare the strength of the traditional transosseus tendon-to-tendon fixation with tendon-to-bone fixation using a tenodesis screw, in cyclical loading and ultimate load testing. Materials and Methods. Tendon grafts were undertaken in 24 paired lower-leg specimens and randomly assigned in two groups using fixation with a transosseus suture (suture group) or a tenodesis screw (screw group). The biomechanical behaviour was evaluated using cyclical and ultimate loading tests. The Student’s t-test was performed to assess statistically significant differences in bone mineral density (BMD), displacement, the slope of the load-displacement curves, and load to failure. Results. The screw group showed less displacement (loosening) during cyclical loading, which was significant during 300, 500, 600, 700, 800, 900, and 1000 cycles (p < 0.05: other cycles: 0.079 < p < 0.402). Compared with the suture group, the screw group had higher mean ultimate load values (133.6 N, . sd. 73.5 vs 110.1 N,. sd. 46.2; p = 0.416). Conclusion. Fixation of the FHL tendon with a tenodesis screw enables a less invasive procedure to be undertaken and shows similar biomechanical behaviour and primary strength compared with fixation using a transosseus suture. Cite this article: Bone Joint J 2018;100-B:1175–81

Aims. Acute and chronic injuries of the interosseus membrane can result in longitudinal instability of the forearm. Reconstruction of the central band of the interosseus membrane can help to restore biomechanical stability. Different methods have been used to reconstruct the central band, including tendon grafts, bone-ligament-bone grafts, and synthetic grafts. This Idea, Development, Exploration, Assessment, and Long-term (IDEAL) phase 1 study aims to review the clinical results of reconstruction using a synthetic braided cross-linked graft secured at either end with an Endobutton to restore the force balance between the bones of the forearm. Methods. An independent retrospective review was conducted of a consecutive series of 21 patients with longitudinal instability injuries treated with anatomical central band reconstruction between February 2011 and July 2019. Patients with less than 12 months’ follow-up or who were treated acutely were excluded, leaving 18 patients in total. Preoperative clinical and radiological assessments were compared with prospectively gathered data using range of motion and the abbreviated version of the Disabilities of the Arm, Shoulder and Hand questionnaire (QuickDASH) functional outcome score. Results. Of the 18 patients (nine male, nine female) who met the inclusion criteria, the median follow-up was 8.5 years (interquartile range (IQR) 5.6 to 10). Their mean age was 49 years (SD 11). The mean extension improved significantly from 38° (SD 15°) to 24° (SD 9°) (p = 0.027), with a mean flexion-extension arc change from 81° (SD 27°) to 93° (SD 30°) (p = 0.172) but with no forearm rotational improvement (p = 0.233) at latest follow-up. The QuickDASH functional score improved significantly from 80 (SD 14) to 52 (SD 26) following reconstruction (p = 0.031), but generally the level of disability remains high. Radiological assessment showed no progression of proximal migration of the radius, with a stable interbutton distance and ulnar variance from immediate postoperative radiograph to the latest follow-up. Conclusion. Central band interosseus membrane reconstruction using a synthetic braided cross-linked graft can improve patient-rated arm function and range of motion, but significant functional deficits remain in patients with chronic injuries. Cite this article: Bone Joint J 2024;106-B(2):182–188

The excursion resistance between the tendon and pulley is an important factor contributing to the limitation of function after surgery to the hand. The administration of hyaluronic acid (HA) in the early rehabilitation after tendon grafting may help to prevent adhesions. We evaluated changes in the excursion resistance between potential sources of flexor tendon grafts and the annular pulley in a canine model after administration of HA. The intrasynovial and extrasynovial tendons were soaked in 10 mg/ml of HA for five minutes. The excursion resistance between these tendons and the annular pulley of an intact proximal phalanx and that of the same tendons of the opposite foot without administration of HA were evaluated. The tendon of flexor digitorum profundus of the second toe without administration of HA was used as a control. The gliding resistance of canine tendons was significantly decreased after the administration of HA especially in the extrasynovial tendons. Our findings suggest that the administration of HA may improve the gliding function of a flexor tendon graft

We investigated whether strontium-enriched calcium phosphate cement (Sr-CPC)-treated soft-tissue tendon graft results in accelerated healing within the bone tunnel in reconstruction of the anterior cruciate ligament (ACL). A total of 30 single-bundle ACL reconstructions using tendo Achillis allograft were performed in 15 rabbits. The graft on the tested limb was treated with Sr-CPC, whereas that on the contralateral limb was untreated and served as a control. At timepoints three, six, nine, 12 and 24 weeks after surgery, three animals were killed for histological examination. At six weeks, the graft–bone interface in the control group was filled in with fibrovascular tissue. However, the gap in the Sr-CPC group had already been completely filled in with new bone, and there was evidence of the early formation of Sharpey fibres. At 24 weeks, remodelling into a normal ACL–bone-like insertion was found in the Sr-CPC group. Coating of Sr-CPC on soft tissue tendon allograft leads to accelerated graft healing within the bone tunnel in a rabbit model of ACL reconstruction using Achilles tendon allograft. Cite this article: Bone Joint J 2013;95-B:923–8

We report the use of a free tendon graft in 70 patients to repair lesions of the capsuloligamentous complex of the metacarpophalangeal joint of the thumb. Of these 37 had a lesion of the ulnar collateral ligament, 18 of the radial collateral and 11 of the volar plate. Four patients had combined lesions. We outline our techniques and review 51 of the patients. Of those 47 (92%) were satisfied, and all but one had regained full stability. Pinch grip strength was normal in 48. About one-third of the patients had some loss of flexion/extension; this was seldom noticed by the patients and caused no significant disability. Free tendon graft reconstruction is indicated for severe fresh lesions, for old lesions with chronic disability and for lesions which have not responded to conservative management

Objectives

This study investigated the biomechanical performance of decellularized porcine superflexor tendon (pSFT) grafts of varying diameters when utilized in conjunction with contemporary ACL graft fixation systems. This aimed to produce a range of ‘off-the-shelf’ products with predictable mechanical performance, depending on the individual requirements of the patient.

Aims

To evaluate the donor site morbidity and tendon morphology after harvesting whole length, full-thickness peroneus longus tendon (PLT) proximal to the lateral malleolus for ligament reconstructions or tendon transfer.

Fresh frozen allogeneic tendon was used to reconstruct the lateral ligaments in 17 ankles. Two or more years later, 13 returned for follow-up examination. The mean age at operation was 23 years (range 15 to 39); the interval between injury and operation varied from six months to 20 years. There were no infections and no immunological rejections, and according to Sefton's criteria, nine patients were excellent and four good. No patient complained of instability of the ankle and stress radiography confirmed this improvement. Allograft reconstruction of the lateral ligaments of the ankle is a new method of treatment which restores stability without sacrificing normal tendons.

The revascularisation and remodelling of allografts used to replace the anterior cruciate ligament in the canine knee were studied by microangiographic, histological and biomechanical methods. The 26 allografts were obtained from the patellar tendons of other dogs and were stored by deep freezing. In a control study a strip of patellar tendon from the same leg was used as an autologous free graft. Microangiography showed that the allografts had been revascularised from the sixth postoperative week, and had later developed an intrinsic vascular pattern similar to that of a normal anterior cruciate ligament. Histologically, the allograft regained a fibrous framework similar to that of a normal ligament, and showed no evidence of immunological rejection. Biomechanical tests on the allograft replacements showed that their mean maximum tensile strength at 30 weeks was about 30% of that of the control ligaments. There were no significant differences between the mechanical properties of the allografts and the autografts.

We describe three patients in whom the tibial nerve was used, in mistake for the plantaris tendon, to repair a ruptured calcaneal tendon. The tendon repair was successful in all cases, but despite attempted reconstruction of the nerve, no patient had any motor recovery although two regained some protective sensation.

We describe the use of allogeneic human tendon as an intra-articular replacement for the anterior cruciate ligament. Depending on the type and degree of functional instability we recommend the addition, in some cases, of supplementary extra-articular procedures. We have reviewed 31 patients at least two years after operation and have found that 30 of them had been able to return to full sporting activities. The indications for operation and the techniques are discussed and the use of allogeneic tendon is recommended.

In order to determine whether an allogeneic tendon could be used to replace an extra-articular ligament, the right medial collateral ligament from 11 adult dogs was replaced with a fresh-frozen allogeneic patellar tendon. At each of 3, 6, 15, 30 and 52 weeks postoperatively, one dog was killed for micro-angiographical and histological studies; at 52 weeks the remaining six dogs were killed for tensile testing. Micro-angiograms showed that the allogeneic tendon was revascularised with infiltration of the mesenchymal cells from the surrounding tissues and both ends of the graft. Histologically, the alignment of the fibroblasts and collagen bundles became more regular over time, without any immunological rejection. A biomechanical study performed at 52 weeks found no significant difference in stiffness or ultimate load between normal and reconstructed ligaments. Fresh-frozen allogeneic tendons are therefore considered useful for extra-articular ligament reconstruction.

The tensile strength of the medial patellofemoral ligament (MPFL), and of surgical procedures which reconstitute it, are unknown. Ten fresh cadaver knees were prepared by isolating the patella, leaving only the MPFL as its attachment to the medial femoral condyle. The MPFL was either repaired by using a Kessler suture or reconstructed using either bone anchors or one of two tendon grafting techniques. The tensile strength and the displacement to peak force of the MPFL were then measured using an Instron materials-testing machine. The MPFL was found to have a mean tensile strength of 208 N (SD 90) at 26 mm (SD 7) of displacement. The strengths of the other techniques were: sutures alone, 37 N (SD 27); bone anchors plus sutures, 142 N (SD 39); blind-tunnel tendon graft, 126 N (SD 21); and through-tunnel tendon graft, 195 N (SD 66). The last was not significantly weaker than the MPFL itself

We present a case of disruption of the posterolateral corner of the knee with avulsion of the tendon of biceps femoris. Repair and reconstruction included an allogenic tendon graft to replace the posterior cruciate ligament. Surgery was followed by a complete common peroneal nerve palsy. Revision surgery revealed that the nerve had been displaced anteriorly by avulsion of the biceps tendon and the tendon graft encircled it. Release of the nerve restored normal function at five months

We describe the intermediate results of lateral ligamentous repair or reconstruction for posterolateral rotatory instability of the elbow. Between 1986 and 1999, we performed 12 direct repairs and 33 ligament reconstructions with a tendon autograft. One patient was lost to follow-up and 44 were retrospectively studied at a mean of six years (2 to 15). Surgery restored stability in all except five patients. In two the elbow became stable after a second procedure. The mean post-operative Mayo elbow performance score was 85 points (60 to 100). The result was classified as excellent in 19, good in 13, fair in seven and poor in five patients. Thirty-eight patients (86%) were subjectively satisfied with the outcome of the operation. Better results were obtained in patients with a post-traumatic aetiology (p = 0.03), those with subjective symptoms of instability at presentation (p = 0.006) and those who had an augmented reconstruction using a tendon graft (p = 0.04). Reconstruction using a tendon graft seems to provide better results than ligament repair and the results do not seem to deteriorate with time. The outcome of this procedure is less predictable in patients with no subjective instability

1. Tendon grafts, in order to survive, have to develop a blood supply from their immediate environment. This causes adhesions. 2. Their final range of movement is therefore a sum of the length to which these vascular adhesions will stretch, and the range of movement of the normal tissues to which the tendon has become adherent. 3. Thus it is important that the tendon graft should lie in a bed of yielding material, and that no unyielding structures should be divided in the same wound. When possible, blunt tunnelling between short transverse incisions is the method of choice for placement of grafts. 4. The most crippling adhesions are those that grow from an imperfectly sutured cut end of tendon, leaving it unsatisfied. A new method of tendon anastomosis designed to prevent such adhesions is described. 5. A tendon grafting technique for intrinsic paralysis of the fingers in leprosy, using a radial extensor of the wrist as the motor and the plantaris tendon as the graft, is described. 6. A study of 861 fingers after the operation is presented. 7. The importance of re-education after operation is stressed