Objectives. After an injury, the biological reattachment of tendon to bone is a challenge because healing takes place between a soft (tendon) and a hard (bone) tissue. Even after healing, the transition zone in the enthesis is not completely regenerated, making it susceptible to re-injury. In this study, we aimed to regenerate Achilles tendon entheses (ATEs) in wounded rats using a combination of kartogenin (KGN) and platelet-rich plasma (PRP). Methods. Wounds created in rat ATEs were given three different treatments: kartogenin platelet-rich plasma (KGN-PRP); PRP; or saline (control), followed by histological and immunochemical analyses, and mechanical testing of the rat ATEs after three months of healing. Results. Histological analysis showed well organised arrangement of collagen fibres and proteoglycan formation in the wounded ATEs in the KGN-PRP group. Furthermore, immunohistochemical analysis revealed fibrocartilage formation in the KGN-PRP-treated ATEs, evidenced by the presence of both collagen I and II in the healed ATE. Larger positively stained collagen III areas were found in both PRP and saline groups than those in the KGN-PRP group. Chondrocyte-related genes, SOX9 and collagen II, and tenocyte-related genes, collagen I and scleraxis (SCX), were also upregulated by KGN-PRP. Moreover, mechanical testing results showed higher ultimate tensile strength in the KGN-PRP group than in the saline control group. In contrast, PRP treatment appeared to have healed the injured ATE but induced no apparent formation of fibrocartilage. The saline-treated group showed poor healing without fibrocartilage tissue formation in the ATEs. Conclusions. Our results show that injection of KGN-PRP induces fibrocartilage formation in the wounded rat ATEs. Hence, KGN-PRP may be a clinically relevant, biological approach to regenerate injured enthesis effectively. Cite this article: J. Zhang, T. Yuan, N. Zheng, Y. Zhou, M. V. Hogan, J. H-C. Wang. The combined use of kartogenin and platelet-rich plasma promotes fibrocartilage formation in the wounded rat Achilles tendon entheses. Bone Joint Res 2017;6:231–244. DOI: 10.1302/2046-3758.64.BJR-2017-0268.R1

Aims

Mechanical stimulation is a key factor in the development and healing of tendon-bone insertion. Treadmill training is an important rehabilitation treatment. This study aims to investigate the benefits of treadmill training initiated on postoperative day 7 for tendon-bone insertion healing.

Aims. Studies on long-term patient-reported outcomes after open surgery for triangular fibrocartilage complex (TFCC) are scarce. Surgeons and patients would benefit from self-reported outcome data on pain, function, complications, and satisfaction after this surgery to enhance shared decision-making. The aim of this study is to determine the long-term outcome of adults who had open surgery for the TFCC. Methods. A prospective cohort study that included patients with open surgery for the TFCC between December 2011 and September 2015. In September 2020, we sent these patients an additional follow-up questionnaire, including the Patient-Rated Wrist Evaluation (PRWE), to score satisfaction, complications, pain, and function. Results. A total of 113 patients were included in the analysis. At ≥ 60 months after an open TFCC reinsertion, we found a mean PRWE total score of 19 (SD 21), a mean PRWE pain score of 11 (SD 11), and a PRWE function score of 9 (SD 10). The percentage of patients obtaining minimum clinically important difference rose from 77% at 12 months to 83% at more than 60 months (p < 0.001). Patients reported fewer complications than surgeons, and overall complication rate was low. Conclusion. Outcomes of patient-reported pain, function scores, and satisfaction are improved five years after open surgery for the TFCC. Cite this article: Bone Jt Open 2021;2(11):981–987

Aims. The study aimed to assess the clinical outcomes of arthroscopic debridement and partial excision in patients with traumatic central tears of the triangular fibrocartilage complex (TFCC), and to identify prognostic factors associated with unfavourable clinical outcomes. Methods. A retrospective analysis was conducted on patients arthroscopically diagnosed with Palmer 1 A lesions who underwent arthroscopic debridement and partial excision from March 2009 to February 2021, with a minimum follow-up of 24 months. Patients were assessed using the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, Mayo Wrist Score (MWS), and visual analogue scale (VAS) for pain. The poor outcome group was defined as patients whose preoperative and last follow-up clinical score difference was less than the minimal clinically important difference of the DASH score (10.83). Baseline characteristics, arthroscopic findings, and radiological factors (ulnar variance, MRI, or arthrography) were evaluated to predict poor clinical outcomes. Results. A total of 114 patients were enrolled in this study, with a mean follow-up period of 29.8 months (SD 14.4). The mean DASH score improved from 36.5 (SD 21.5) to 16.7 (SD 14.3), the mean MWS from 59.7 (SD 17.9) to 79.3 (SD 14.3), and the mean VAS pain score improved from 5.9 (SD 1.8) to 2.2 (SD 2.0) at the last follow-up (all p < 0.001). Among the 114 patients, 16 (14%) experienced poor clinical outcomes and ten (8.8%) required secondary ulnar shortening osteotomy. Positive ulnar variance was the only factor significantly associated with poor clinical outcomes (p < 0.001). Positive ulnar variance was present in 38 patients (33%); among them, eight patients (21%) required additional operations. Conclusion. Arthroscopic debridement alone appears to be an effective and safe initial treatment for patients with traumatic central TFCC tears. The presence of positive ulnar variance was associated with poor clinical outcomes, but close observation after arthroscopic debridement is more likely to be recommended than ulnar shortening osteotomy as a primary treatment. Cite this article: Bone Joint J 2024;106-B(4):380–386

Aims. Patients with a triangular fibrocartilage complex (TFCC) injury report ulnar-sided wrist pain and impaired function. The surgical procedure of TFCC reinsertion aims to improve function in patients with this injury in whom conservative treatment has failed. The purpose of this study was to investigate the outcomes of open TFCC reinsertion. Methods. The study involved 274 patients who underwent open repair of the TFCC between December 2013 and December 2018. The patients completed the Patient-Rated Wrist Evaluation (PRWE) questionnaire, and scored pain and function using a visual analogue scale (VAS). Range of motion (ROM) was assessed by experienced hand therapists. Results. Clinically significant improvements were reported in pain, function, and grip strength in 220 patients (80%) three and 12 months postoperatively. Conclusion. These data will help surgeons to make decisions about the outcomes of open repair of the TFCC and to counsel patients appropriately. Level of evidence: III. Cite this article: Bone Joint J 2021;103-B(4):711–717

Aims. The primary aim of this study was to assess if traumatic triangular fibrocartilage complex (TFCC) tears can be treated successfully with immobilization alone. Our secondary aims were to identify clinical factors that may predict a poor prognosis. Methods. This was a retrospective analysis of 89 wrists in 88 patients between January 2015 and January 2019. All patients were managed conservatively initially with either a short-arm or above-elbow custom-moulded thermoplastic splint for six weeks. Outcome measures recorded included a visual analogue scale for pain, Patient-Rated Wrist Evaluation, Disabilities of the Arm, Shoulder and Hand score, and the modified Mayo Wrist Score (MMWS). Patients were considered to have had a poor outcome if their final MMWS was less than 80 points, or if they required eventual surgical intervention. Univariate and logistic regression analyses were used to identify independent predictors for a poor outcome. Results. In total, 76% of wrists (42/55) treated with an above-elbow splint had a good outcome, compared to only 29% (10/34) with a short-arm splint (p < 0.001). The presence of a complete foveal TFCC tear (p = 0.009) and a dorsally subluxated distal radioulnar joint (DRUJ) (p = 0.032) were significantly associated with a poor outcome on univariate analysis. Sex, age, energy of injury, hand dominance, manual occupation, ulnar variance, and a delay in initial treatment demonstrated no significant association. Multiple logistic regression revealed that short-arm immobilization (p < 0.001) and DRUJ subluxation (p = 0.020) were significant independent predictive factors of an eventual poor outcome. Conclusion. Nonoperative management of traumatic TFCC injuries with above-elbow immobilization is a viable treatment method, particularly in patients without DRUJ subluxation. Early surgery should be considered for patients with dorsal ulnar subluxation treated with short-arm splints to prevent prolonged morbidity. Cite this article: Bone Joint J 2021;103-B(8):1386–1391

We report the case of a 24-year-old man with a congenital meniscoid articular disc of the triangular fibrocartilage complex with extensor carpi ulnaris tenosynovitis. His young age, the normal articular cartilage, the lack of degenerative changes at the margins of the defect and its bilateral occurrence made this diagnosis likely. A congenital defect of the articular disc of the triangular fibrocartilage complex should not be misinterpreted as a traumatic rupture and is usually asymptomatic

Aims. The aim of this study was to assess and compare active rotation of the forearm in normal subjects after the application of a short-arm cast (SAC) in the semisupination position and a long-arm cast (LAC) in the neutral position. A clinical study was also conducted to compare the functional outcomes of using a SAC in the semisupination position with those of using a LAC in the neutral position in patients who underwent arthroscopic triangular fibrocartilage complex (TFCC) foveal repair. Methods. A total of 40 healthy right-handed volunteers were recruited. Active pronation and supination of the forearm were measured in each subject using a goniometer. In the retrospective clinical study, 40 patients who underwent arthroscopic foveal repair were included. The wrist was immobilized postoperatively using a SAC in the semisupination position (approximately 45°) in 16 patients and a LAC in 24. Clinical outcomes were assessed using grip strength and patient-reported outcomes. The degree of disability caused by cast immobilization was also evaluated when the cast was removed. Results. Supination was significantly more restricted with LACs than with SACs in the semisupination position in male and female patients (p < 0.001 for both). However, pronation was significantly more restricted with SACs in the semisupination position than with LACs in female patients (p = 0.003) and was not significantly different in male patients (p = 0.090). In the clinical study, both groups showed improvement in all parameters with significant differences in grip strength, visual analogue scale scores for pain, modified Mayo Wrist Score, the Disability of the Arm, Shoulder, and Hand (DASH) score, and the Patient-Rated Wrist Evaluation (PRWE) score. No significant postoperative differences were noted between LACs and SACs in the semisupination position. However, the disability caused by immobilization in a cast was significantly higher in patients who had a LAC on the dominant hand (p < 0.001). Conclusion. We found that a SAC in the semisupination position is as effective as a LAC in restricting pronation of the forearm. In addition, postoperative immobilization with a SAC in the semisupination position resulted in comparable pain scores and functional outcomes to immobilization with a LAC after TFCC foveal repair, with less restriction of daily activities. Therefore, we recommend that surgeons consider using a SAC in the semisupination position for postoperative immobilization following TFCC foveal repair for dorsal instability of the distal radioulnar joint. Cite this article: Bone Joint J 2022;104-B(2):249–256

Bone tendon junction (BTJ) healing after injury is often slow, without restoration of fibrocartilage transition zone. Fibrocartilage formation has been observed near articular cartilage. It was hypothesised that articular cartilage interposition could stimulate fibrocartilage transition zone regeneration and improve BTJ healing. Partial patellectomy repair was performed in goat. Articular cartilage harvested from excised patella segment was interposed between the patella and patellar tendon during repair. No cartilage interposition was used in control group. Samples were harvested at six, 12, and 24 weeks for histological examination (n=6 each). The histological images were digitised and analyzed using an image analysis system. Healing progress was assessed by the amount of new bone formation and fibrocartilage transition zone regeneration. Quantitative data were analyzed using SPSS version 14.0. Statistic al significance level was set at p < 0.05. There was progressive increase in maximum new bone length and area of new bone formed with time (p< 0.05, Kruskal-Wallis test). No difference was observed between treatment groups. Articular cartilage interposition resulted in more fibrocartilage regeneration and higher proteoglycan uptake at all time points. At 24 weeks, length of fibrocartilage formed measured 7760 ± 629 μm with articular cartilage interposition, compared with 787± 274 μm in control (p = 0.002, Mann-Whitney test). Safranin O length measured 3301 ± 1236 μm with articular cartilage interposition, compared with 277 ± 187 μm in control (p = 0.03, Mann-Whitney test). Autologous articular cartilage interposition stimulates fibrocartilage transition zone regeneration in BTJ repair without affecting bone formation

Summary Statement. The Dkk3-derived cells represent a branch of the periosteal mesenchymal lineage that produces fibrocartilage as well as regenerating the periosteal structures. Introduction. Mesenchymal progenitor cells are capable of generating a wide variety of mature cells that constitute the connective tissue system. Our Laboratory has been developing SMAA GFP reporter mice to prove to be an effective tool for identifying these cells prior to the expression of markers of differentiation characteristic of bone, fat, muscular blood vessels or fibrocartilage. Dkk3 was chosen as a candidate reporter because microarray of SMAA-sorted cells culture indicated high expression of this non-canonical anti-Wnt factor, which was not anticipated in a culture with strong osteogenic potential. Material and Methods. Fracture healing process was evaluated in 12 week old male mice at 3, 5, 7, 14, 21 and 28days post fracture. A 3 color reporter mouse was generated by crossing SMAA-GFPcherry × Col3.6GFPcyan × Dkk3-eGFP and subjected to tibial fracture. A closed transverse fracture was performed by Einhorn device under isoflurane anesthesia after insertion of intramedullary pinning. Longitudinal 5 mm non-calcified cryosections were stabilised with Cryofilm tape. Results. Three days post fracture, the proliferating SMAA-red cells were also beginning to express either Dkk3 or Col3.6. By day 5 the two populations had diverged with the Dkk3 cells being on the outer surface of the developing callus while the Col3.6 cells were forming bone at the base of the callus. By day 7 when the callus is filled with cartilage, Dkk3 is active in cells that are in transition from elongated cells on the external surface of the callus to fibrocartilagenous cells that now express low levels of Col3.6. The zone of cells that express Dkk3 appear to block the passage of the surrounding vasculature into the underlying cartilage and does not deposit fibronectin. By day 14–21 when the cartilage core is resorbed, the only remaining Dkk3 is located in the newly formed periosteum external to the active endocortical bone forming activity associated with the inward remodeling of the outer cortical shell. Discussion. We interpret these findings that Dkk3 marks a non-osteogenic limb of the SMAA progenitor population that within the fracture partitions the osteogenic signals away from the surrounding skeletal muscle and the underlying differentiating fibrocartilage. It is a progenitor to cells that form fibrocartilage in the fracture zone as well as the tenascin C positive cells that populate the fibrous zone of the periosteum, and it resides in the cambial zone of the periosteum. Knowing the biological and molecular function of these cells should lead to a fuller appreciation of the pro- and anti-osteogenic factors that regulate skeletal repair

Aims. The aim of this study was to analyze the association between the shape of the distal radius sigmoid notch and triangular fibrocartilage complex (TFCC) foveal tear. Methods. Between 2013 and 2018, patients were retrospectively recruited in two different groups. The patient group comprised individuals who underwent arthroscopic transosseous TFCC foveal repair for foveal tear of the wrist. The control group comprised individuals presenting with various diseases around wrist not affecting the TFCC. The study recruited 176 patients (58 patients, 118 controls). The sigmoid notch shape was classified into four types (flat-face, C-, S-, and ski-slope types) and three radiological parameters related to the sigmoid notch (namely, the radius curvature, depth, and version angle) were measured. The association of radiological parameters and sigmoid notch types with the TFCC foveal tear was investigated in univariate and multivariate analyses. Receiver operating characteristic curves were used to estimate a cut-off for any statistically significant variables. Results. Univariate analysis showed that the flat-face type was more prevalent in the patients than in the control group (43% vs 21%; p = 0.002), while the C-type was lower in the patients than in the control group (3% vs 17%; p = 0.011). The depth and version angle of sigmoid notch showed a negative association with the TFCC foveal tear in the multivariate analysis (depth: odds ratio (OR) 0.380; p = 0.037; version angle: OR 0.896; p = 0.033). Estimated cut-off values were 1.34 mm for the depth (area under the curve (AUC) = 0.725) and 10.45° for the version angle (AUC = 0.726). Conclusion. The proportion of flat-face sigmoid notch type was greater in the patient group than in the control group. The depth and version angle of sigmoid notch were negatively associated with TFCC foveal injury. Cite this article: Bone Joint J 2020;102-B(6):749–754

Abstract. Background. We know that tears of the Triangular fibrocartilage complex (TFCC) can cause DRUJ instability and ulnar sided wrist pain. This study shows the clinical result of patients who had arthroscopic transosseous repair of the TFCC tear with DRUJ instability. Arthroscopic repair of TFCC tear is a promising, minimally invasive surgical technique especially in patients with DRUJ instability. Materials and methods. Fifteen patients who underwent TFCC one tunnel repair form 2018–2021 were reviewed retrospectively in hospital. The proximal component of TFCC was repaired through arthroscopic one- tunnel transosseous suture technique. VAS score for pain, wrist range of motion, grip strength and post operative complications were evaluated and each patient was rated according to the DASH score. Results. The patients had a TFCC tear confirmed on MRI and was confirmed on arthroscopy by doing a hook test. The patients were followed up for 6 months. Twelve patients had normal stability of DRUJ and three patients showed mild laxity compared with the contralateral side. The mean VAS score reduced from 4.7 to 0.8 (P=0.001) and grip strength increased significantly. The quick DASH score (P=0.001)also showed significant functional improvement. No surgical related complications occurred. Conclusions. Arthroscopic one tunnel transosseous TFCC foveal repair can be an excellent and safe method for repair of TFCC tear with DRUJ instability. Its a good treatment option in terms of reliable pain relief, functional improvement and reestablishment of DRUJ stability

The enthesis is a tissue interface between tendon and bone, essential for adequate force transmission and composed by four distinct zones, namely tendon, fibrocartilage, mineralized fibrocartilage and bone. Given the avascularity of the tendon and the gradual change in tissue architecture and cell phenotype, the enthesis original tissue is often not re-established after chronic injuries, resulting in scar formation. Conservative treatments and surgical approaches are still far from a functional regeneration, whilst tissue engineering based scaffolds have recently showed great potential. In this work, we hypothesised that collagen-based scaffolds that mimic the basic architecture of the enthesis, will be able to spatially direct stem cell differentiation, providing an in vitro platform to study enthesis regeneration. A three-layer sponge composed of a tendon-like layer (collagen type I), a fibrocartilage-like layer (collagen type II) and a bone-like layer (collagen type I and hydroxyapatite) was fabricated by an iterative layering freeze-drying technique. Scaffold pore size and structural continuity at the interfaces were assessed by SEM and μ-CT analysis. Bone-marrow derived stem cells (BMSCs) were seeded on the scaffold and cultured in basal and differentiation media (chondrogenic, tenogenic and osteogenic). At day 7 and 21 the scaffolds were stained with Alizarin Red and Alcian Blue; alkaline phosphatase activity (ALP) and calcium and glycosaminoglycans (GAGs) were quantified in order to evaluate BMSC differentiation towards osteogenic and chondrogenic lineage. The presence of collagen I, III, tenascin and decorin in the scaffolds was evaluated by immunofluorescence staining in order to evaluate tenogenic differentiation of BMSCs. Scaffolds with three distinct but interconnected layers of collagen type I, collagen type II and collagen type I + hydroxyapatite were fabricated, with pore sizes in the range of 100–200 μm. Increased ALP and calcium levels were detected in a localised manner within the bone-like layer when scaffolds were cultured in basal medium (p<0.025 vs the other 2 layers). Similarly, proteoglycans were detected specifically in the fibrocartilage-like layer when scaffolds were cultured in the chondrogenic differentiation medium (p<0.03 vs the other 2 layers). Increased expression of tenogenic markers was observed in the tendon-like layer of scaffolds cultured in tenogenic media (p<0.045 vs the other 2 layers). In conclusion, the different collagen composition of each layer was able to spatially direct BMSC differentiation in a localized manner within the scaffold. Ongoing work is evaluating the synergistic effect between growth factor functionalized within the fibrocartilage and tendon-like layers for improved BMSC differentiation. Overall, these scaffolds hold promising potential in developing novel and more efficient strategy towards enthesis regeneration

There is a difference of opinion regarding the usefulness of MR Imaging as a diagnostic tool for triangular fibrocartilage complex (TFCC) tears in the wrist. Our aim was to determine the accuracy of direct magnetic resonance arthrography (MRA) in the diagnosis of triangular fibrocartilage complex (TFCC) tears of the wrist in a district general hospital setting. In a retrospective review of 21 patients who presented with complains of wrist pain and following a clinical examination, all had direct MR arthrography of the wrist in our hospital in a 1.5Tesla scanner. All had a diagnostic arthroscopy within 2-4 months of the MR scan. All patients had chronic ulnar sided wrist pain, although only two had a definite history of trauma. The findings of each diagnostic method were compared, with arthroscopy considered the gold standard. Twenty-one patients were studied (10 male: 11 female), mean age 42 years (range 27-71) years). Seventeen TFCC tears were diagnosed on arthroscopy. For the diagnosis of TFCC tears MRA had a sensitivity, specificity and accuracy of 67%. Our results echoed the opinion of some of the previous investigators with an unacceptable sensitivity or specificity for a diagnostic tool. MR arthrography needs to be further refined as a technique before it can be considered to be accurate enough to replace wrist arthroscopy for the diagnosis of TFCC tears. Other centres have reported better accuracy, using more advanced MRI technology. Until this iswidely available at all levels of healthcare the results of MRI for the diagnosis of TFCC tears should be interpreted with caution

There have been few descriptions of the site of attachment onto the triquetrum, the so-called meniscal homologue, of the triangular fibrocartilage complex (TFCC). We have investigated the sites of attachment onto the triquetrum of 87 TFCCs collected from embalmed cadavers. All TFCCs were smoothly attached to the triquetrum. In 79 (46 cases, 90%) they were attached to the triquetrum and fifth metacarpal bone, and in eight (5 cases, 10%) they were attached widely on the articular surface of the triquetrum. It is necessary to have accurate positional information about the normal triquetrum and TFCC in order to perform arthroscopy. The meniscal homologue attached to the triquetrum is smooth in almost all cases. In about 10% of joints the TFCC is attached to the lunotriquetral ligament, either partly or completely obscuring the articular surface of the triquetrum

Purpose: The purpose of this study was to evaluate the long-term results of arthroscopic treatment in patients affected by triangular fibrocartilage complex (TFCC) type 1b lesions associated with distal radio ulnar joint (DRUJ) instability. Method: 138 patients affected by TFCC type 1b lesions: Group A (117 patients, 27±7 yrs) were treated using an out-in arthroscopic technique and Group B (21 patients, 24±4 yrs) with an associated total DRUJ instability, were treated using an out-in arthroscopic technique in addition to an anchor placement. Inclusion criteria were: TFCC tears, type 1b lesions and no previous wrist fractures. SF-36, DASH, VAS, and ROM were accessed preoperatively and at four years follow-up. Results: All the patients have a significant improvement in terms of SF-36 (p0.05). Conclusion: Arthroscopy is a tool of paramount importance in both diagnosis and treatment of TFCC injuries even associated with DRUJ. Furthermore, type 1b lesions associated with total DRUJ instability should be managed combining an out-in arthroscopic technique with the use of an anchor to completely relieve pain and restore wrist function

Summary. When a TFCC tear is diagnosed, practitioners should maintain a high level of suspicion for the presence of a concomitant SL or LT ligament tear. Introduction. Disruption of the scapholunate (SL) or lunotriquetral (LT) ligament leads to dorsal and volar intercalated segment instability, respectively, while triangular fibrocartilage complex (TFCC) tears result in distal radioulnar joint (DRUJ) instability. Viegas et al. (1993) demonstrated that 56% of grossly visualised cadaveric wrists had one or more tears of a ligament or of the TFCC. The purpose of this investigation is to quantify the incidence, distribution, and correlation of SL, LT, and TFCC tears in a large group of cadaver wrists using magnetic resonance imaging (MRI). Additionally, statistical analysis was performed to predict. Methods. Spin density weighted, fat suppressed, and STIR MRI scans of the wrist were obtained in 48 fresh frozen cadaver arms using a 3 Tesla MRI scanner. The scans were scrutinised by one of us (PC) – a board certified musculoskeletal radiologist. The dorsal, volar, and membranous portions of the SL and LT ligaments were examined sequentially for the presence of a tear. Similarly, the central disk and radioulnar attachments of the TFCC were inspected for tears. Results. A ligament or the TFCC was labeled as torn if there was a complete tear, partial tear, or perforation of one or more of its components, but not if sole degenerative changes, thinning, or fraying of the fibers was observed. Four of the 48 images could not be interpreted due to unsatisfactory scans. The most prevalent injury was a TFCC tear, which was present in 28 (64%) of the 44 wrists examined. SL ligament tears were discovered in 20 (45%) of the wrists, and LT tears were present in 14 (32%) of the wrists. Moreover, 45% of the wrists examined had a TFCC tear and either a SL or LT ligament tear. Specifically, 50% of the 28 wrists with a TFCC tear had a concomitant LT tear, and 46% had a concomitant SL tear. Discussion. SL, LT, and TFCC tears were found in a substantial portion of the wrists examined. Moreover, the majority of wrists with a TFCC tear also had a SL or LT ligament tear. Viegas et al. found that 70% of wrists with a TFCC perforation also had a LT ligament tear. In our series, 71% had a TFCC tear, and 50% of those had a concomitant LT tear

Introduction. We reports the accuracy of direct Magnetic Resonance Arthrography (MRA) in detecting Triangular Fibrocartilage Complex (TFCC), Scapho-Lunate Ligament (SLL) and Luno-Triquetral Ligament (LTL) tears using wrist arthroscopy as the gold standard. Methods. We reviewed the records of all patients who underwent direct wrist MRA and subsequent arthroscopy over a 4-year period between June 2007 and March 2011. Demographic details, MRA findings, arthroscopy findings and the time interval between MRA and arthroscopy were recorded. The scans were performed using a 1.5T scanner and a high resolution wrist coil. All scans were reported by a musculoskeletal radiologist. Sensitivity, specificity, positive and negative predictive values (PPV & NPV) were calculated. Results. Two hundred and thirty four (234) MRA were performed over the study period. Fifty patients (50), who subsequently underwent 51 wrist arthroscopies (one bilateral), were included. The mean age was 35 years (range 16–64 years). The average delay between MRA and arthroscopy was 4.8 months (median 4 months, range 17 days–18 months). All patients were symptomatic with wrist pain. At arthroscopy, 26 TFCC tears, 7 SLL tears and 3 LTL tears were found. For TFCC, sensitivity was 96%, specificity 88%, PPV 89% and NPV 96%. For SLL, the values were 57%, 66%, 21% and 91% respectively. For LTL, 67%, 79%, 17% and 97%, respectively. Receiver Operating Characteristic (ROC) curve analysis showed that MRA only reliably differentiates between patients with and without TFCC tears (Area Under Curve AUC = 0.92, p < 0.0001) but not SLL (AUC = 0.62, p=0.28) or LTL (AUC = 0.73, p=0.17) tears. Conclusion. MRA is a sensitive and specific imaging modality for diagnosing TFCC tears. However, the diagnostic accuracy for SLL and LTL tears was not satisfactory. Wrist arthroscopy remains the gold standard if there is a clinical suspicion of inter-carpal ligament tears

Despite extensive research aimed at improving surgical outcomes of enthesis injuries, re-tears remain a common problem, as the repairs often lead to fibrovascular scar as opposed to a zonal enthesis. Zonal enthesis formation involves anchoring collagen fibers, synthesizing proteoglycan-rich fibrocartilage, and mineralizing this fibrocartilage [1]. During development, the hedgehog signaling pathway promotes the formation and maturation of fibrocartilage within the zonal tendon-to-bone enthesis [1-4]. However, whether this pathway has a similar role in adult zonal tendon-to-bone repair is not known. Therefore, we developed a murine anterior cruciate ligament (ACL) reconstruction model [5] to better understand the zonal tendon-to-bone repair process and perturb key developmental regulators to determine the extent to which they can promote successful repair in the adult. In doing so, we activated the hedgehog signaling pathway both genetically using transgenic mice and pharmacologically via agonist injections. We demonstrated that both treatments improved the formation of zonal attachments and tunnel integration strength [6]. These improved outcomes were due in part to hedgehog signaling's positive role in proliferation of the bone marrow stromal cell (bMSC) progenitor pool and subsequent fibrocartilage production of bMSC progeny cells that form the attachments. These results suggest that, similar to growth and development, hedgehog signaling promotes the production and maturation of fibrocartilage during tendon-to-bone integration in adults. Lastly, we developed localized drug delivery systems to further improve the treatment of these debilitating injuries in future translational studies. Acknowledgements: This work was supported by NIH R01AR076381, R21AR078429, R00AR067283, F31AR079840, T32AR007132, and P30AR069619, in addition to the McCabe Fund Pilot Award at the University of Pennsylvania

Injury to the triangular fibrocartilage complex (TFCC) may result in ulnar wrist pain with or without instability. One component of the TFCC, the radioulnar ligaments, serve as the primary soft-tissue stabilizer of the distal radioulnar joint (DRUJ). Tears or avulsions of its proximal, foveal attachment are thought to be associated with instability of the DRUJ, most noticed during loaded pronosupination. In the absence of detectable instability, injury of the foveal insertion of the radioulnar ligaments may be overlooked. While advanced imaging techniques such as MRI and radiocarpal arthroscopy are well-suited for diagnosing central and distal TFCC tears, partial and complete foveal tears without instability may be missed without a high degree of suspicion. While technically challenging, DRUJ arthroscopy provides the most accurate method of detecting foveal abnormalities. In this annotation the spectrum of foveal injuries is discussed and a modified classification scheme is proposed. Cite this article: Bone Joint J 2023;105-B(1):5–10

The February 2023 Wrist & Hand Roundup. 360. looks at: ‘Self-care’ protocol for minimally displaced distal radius fractures; Treatment strategies for acute Seymour fractures in children and adolescents: including crushed open fractures; Routinely collected outcomes of proximal row carpectomy; Moving minor hand surgeries in the office-based procedure room: a population-based trend analysis; A comparison between robotic-assisted scaphoid screw fixation and a freehand technique for acute scaphoid fracture: a randomized, controlled trial; Factors associated with conversion to surgical release after a steroid injection in patients with a trigger finger; Two modern total wrist arthroplasties: a randomized comparison; Triangular fibrocartilage complex suture repair reliable even in ulnar styloid nonunion

The June 2023 Wrist & Hand Roundup. 360. looks at: Residual flexion deformity after scaphoid nonunion surgery: a seven-year follow-up study; The effectiveness of cognitive behavioural therapy for patients with concurrent hand and psychological disorders; Bite injuries to the hand and forearm: analysis of hospital stay, treatment, and costs; Outcomes of acute perilunate injuries - a systematic review; Abnormal MRI signal intensity of the triangular fibrocartilage complex in asymptomatic wrists; Patient comprehension of operative instructions with a paper handout versus a video: a prospective, randomized controlled trial; Can common hand surgeries be undertaken in the office setting?; The effect of corticosteroid injections on postoperative infections in trigger finger release

The June 2024 Wrist & Hand Roundup. 360. looks at: One-year outcomes of the anatomical front and back reconstruction for scapholunate dissociation; Limited intercarpal fusion versus proximal row carpectomy in the treatment of SLAC or SNAC wrist: results after 3.5 years; Prognostic factors for clinical outcomes after arthroscopic treatment of traumatic central tears of the triangular fibrocartilage complex; The rate of nonunion in the MRI-detected occult scaphoid fracture: a multicentre cohort study; Does correction of carpal malalignment influence the union rate of scaphoid nonunion surgery?; Provision of a home-based video-assisted therapy programme in thumb carpometacarpal arthroplasty; Is replantation associated with better hand function after traumatic hand amputation than after revision amputation?; Diagnostic performance of artificial intelligence for detection of scaphoid and distal radius fractures: a systematic review

For chondral damage in younger patients, surgical best practice is microfracture, which involves drilling into the bone to liberate the bone marrow. This leads to a mechanically inferior fibrocartilage formed over the defect as opposed to the desired hyaline cartilage that properly withstands joint loading. While some devices have been developed to aid microfracture and enable its use in larger defects, fibrocartilage is still produced and there is no clear clinical improvement over microfracture alone in the long term. Our goal is to develop 3D printed devices, which surgeons can implant with a minimally invasive technique. The scaffolds should match the functional properties of cartilage and expose endogenous marrow cells to suitable mechanobiological stimuli in-situ, in order to promote healing of articular cartilage lesions before they progress to osteoarthritis, and rapidly restore joint health and mobility. Importantly, scaffolds should direct a physiological host reaction, instead of a foreign body reaction, associated with chronic inflammation and fibrous capsule formation, negatively influencing the regenerative outcome. Our novel silica/polytetrahydrofuran/polycaprolactone hybrids were prepared by sol-gel synthesis and scaffolds were 3D printed by direct ink writing. 3D printed hybrid scaffolds with pore channels of ~250 µm mimic the compressive behaviour of cartilage. Our results show that these scaffolds support human bone marrow stem/stromal cell (hMSC) differentiation towards chondrogenesis in vitro under hypoxic conditions to produce markers integral to articular cartilage-like matrix evaluated by immunostaining and gene expression analysis. Macroscopic and microscopic evaluation of subcutaneously implanted scaffolds in mice showed that scaffolds caused a minimal resolving inflammatory response. Our findings show that 3D printed hybrid scaffolds have the potential to support cartilage regeneration. Acknowledgements: Authors acknowledge funding provided by EPSRC grant EP/N025059/1

The anterior cruciate ligament (ACL) is the connective tissue located at the end of long bones providing stability to the knee joint. After tear or rupture clinical reconstruction of the tissue remains a challenge due to the particular mechanical properties required for proper functioning of the tissue. The outstanding mechanical properties of the ACL are characterized by a viscoelastic behavior responsible of the dissipation of the loads that are transmitted to the bone. These mechanical properties are the result of a very specialized graded extracellular matrix that transitions smoothly between the heterotypic cells, stiffness and composition of the ACL and the adjacent bone. Thus, mimicking the zonal biochemical composition, cellular phenotype and organization are key to reset the proper functioning of the ACL. We have previously shown how the biochemical composition presented to cells in electrospun scaffolds results in haptokinesis, reverting contact-guidance effects. [1]. Here, we demonstrate that contact guidance can also be disrupted by structural parameters in aligned wavy scaffolds. The presentation of a wavy fiber arrangement affected the cell organization and the deposition of a specific ECM characteristic of fibrocartilage. Cells cultured in wavy scaffolds grew in aggregates, deposited an abundant ECM rich in fibronectin and collagen II, and expressed higher amounts of collagen II, X and tenomodulin as compared to aligned scaffolds. In-vivo implantation in rabbits of triphasic scaffolds accounting for aligned-wavy-aligned zones showed a high cellular infiltration and the formation of an oriented ECM, as compared to traditional aligned scaffolds. [2]

The triangular fibrocartilage complex (TFCC) is a known stabiliser of the distal radioulnar joint (DRUJ). An injury to these structures can result in significant disability including pain, weakness and joint stiffness. The contribution each of its components makes to the stability of the TFCC is not well understood. This study was undertaken to investigate the role of the individual ligaments of the TFCC and their contribution to joint stability. The study was undertaken in two parts. 30 cadaveric forearms were studied in each group. The ligaments of the TFCC were progressively sectioned and the resulting effect on the stability of the DRUJ was measured. A custom jig was created to apply a 20N force through the distal radius, with the ulna fixed. Experiment one measured the effect on DRUJ translation after TFCC sectioning. Experiment two added the measurement of rotational instability. Part one of the study showed that complete sectioning of the TFCC caused a mean increase in translation of 6.09(±3) mm. Sectioning the palmar radioulnar ligament of the TFCC caused the most translation. Part two demonstrated a change in rotation with a mean of 18 (± 6) degrees following sectioning of the TFCC. There was a progressive increase in rotational instability until the palmar radioulnar ligament was also sectioned. Linear translation consistently increased after sectioning all of the TFCC ligaments, confirming its importance for DRUJ stability. Sectioning of the palmar radioulnar ligament most commonly caused the greatest degree of translation. This suggests injury to this ligament would more likely result in a greater degree of translational instability. The increase in rotation also suggests that this type of instability would be symptomatic in a TFCC injury

Cartilage lacks the ability to self-repair when damaged, which can lead to the development of degenerative joint disease. Despite intensive research in the field of cartilage tissue engineering, there is still no regenerative treatment that consistently promotes the development of hyaline cartilage. Extracellular matrix (ECM) derived hydrogels have shown to support cell adhesion, growth and differentiation [1,2]. In this study, porcine articular cartilage was decellularized, solubilised and subsequently modified into a photo-crosslinkable methacrylated cartilage ECM hydrogel. Bone marrow derived mesenchymal stem/stromal cells (MSCs) were encapsulated into both methacrylated ECM hydrogels (ECM-MA) and gelatin methacryloyl (GelMA) as control hydrogel, and their chondrogenic potential was assessed using biochemical assays and histological analysis. We found that successful decellularization of the cartilage tissue could be achieved while preserving key ECM components, including collagen and glycosaminoglycans. A live-dead assay demonstrated good viability of MSCs withing both GelMA and ECM-MA hydrogels on day 7. Large increases in sGAG accumulation was observed after 21 days of culture in chondrogenic media in both groups. Histological analysis revealed the presence of a more fibrocartilage tissue in the GelMA group, while cells embedded within the ECM-MA showed a round and chondrocytic-like morphology. Both groups stained positively for proteoglycans and collagen, with limited evidence of calcium deposition following Alizarin Red staining. These results show that ECM-MA hydrogels support a hyaline cartilage phenotype and robust cartilaginous matrix production. Future studies will focus on the printability of ECM-MA hydrogels to enable their use as bioinks for the biofabrication of functional tissues

The fibrocartilaginous enthesis displays a complex interface between two mechanically dissimilar tissues, namely tendon and bone. This graded transition zone consists of parallel collagen type I fibres arising from the tendon and inserting into bone across zones of fibrocartilage with aligned collagen type I and collagen type II fibres and mineralised fibrocartilage. Due the high stress concentrations arising at the interface, entheses are prone to traumatic and chronic overuse injuries such as rotator cuff and anterior cruciate ligament (ACL) tears. Treatment strategies range from surgical reattachment for complete tears and conservative treatments (physiotherapy, anti-inflammatory drugs) in chronic inflammatory conditions. Generally, the native tissue architecture is not re-established and mechanically inferior scar tissue is formed. Current interfacial tissue engineering approaches pose scaffold-associated drawbacks and limitations, such as foreign body response. Using a thermo-responsive electrospun scaffold that provides architectural signals similar to native tissues and can be removed prior to implantation, we aim to develop an ECM-rich, cell-based implant for tendon-enthesis regeneration. Alcian blue staining revealed highest sGAG deposition in cell (human adipose derived stem cells) sheets grown on random electrospun fibres and lowest sGAG deposition in collagen type I sponges. Cells did not show an equal distribution throughout the collagen type II scaffolds but tended to form localised aggregates. Thermo-responsive electrospun fibres with random and aligned fibre orientation provided an adequate three-dimensional environment for chondrogenic differentiation of multilayer hADSC-sheets shown by high ECM-production, especially high sGAG deposition. Chondrogenic cell sheets showed increased expression of SOX9, COL2A1, COL1A1, COMP and ACAN after 7 days of chondrogenic induction when compared to pellet culture. Anisotropic fibres enabled the generation of aligned chondrogenic cell sheets, shown by cell and collagen fibre alignment. Thermoresponsive electrospun fibres showed high chondro-inductivity due to their three-dimensionality and therefore pose a promising tool for the generation of scaffold-free multilayer constructs for tendon-enthesis repair within short culture periods. Aligned chondrogenic cell sheets mimic the zonal orientation of the native enthesis as the fibrocartilaginous zone exhibits high collagen alignment

Lesions in the joint surface are commonly treated with osteoarticular autograft transfer system (OATS), autologous cell implantation (ACI/MACI), or microfracture. Tissue formed buy the latter commonly results in mechanically inferior fibrocartilage that fails to integrate with the surrounding native cartilage, rather than durable hyaline cartilage. Fractional laser treatment to make sub-millimeter (<500 µm) channels has been employed for tissue regeneration in the skin to facilitate rejuvenation without typical scarring. Additionally, we have pioneered a means to generate articular cartilage matrix from chondrocytes—dynamic Self-Regenerating Cartilage (dSRC). Combining these two approaches by performing fractional laser treatment of the joint cartilage and treating with dSRC is a new paradigm for joint surface restoration. This approach was refined in a series of in vitro experiments and tested in swine knee defects during a 6-month study in 12 swine. dSRC are generated by placing 10. 7. swine knee chondrocytes into sealed 15-mL polypropylene tubes and cultured on a rocker at 40 cycles per minute for 14 days at 37°C. The chondrocytes aggregate and generate new extracellular matrix to form a pellet of dSRC. Channels of approximately 300-500 µm diameter were created by infrared laser ablation in swine cartilage (in vitro) and swine knees (in vivo). The diameter and depth of the ablated channel in the cartilage was controlled by the light delivery parameters (power, spot size, pulse duration) from a fractional 2.94 µm Erbium laser. The specimens were evaluated with histology (H&E, safranin O, toluidine blue) and polarized-sensitive optical coherence tomography for collagen orientation. We can consistently create laser-ablated channels in the swine knee and successfully implant new cartilage from dSRC to generate typical hyaline cartilage in terms of morphology and biochemical properties. The neocartilage integrates with host cartilage in vivo. These findings demonstrate our novel combinatorial approach for articular cartilage rejuvenation

Successful anterior cruciate ligament (ACL) reconstructions strive a firm ligament-bone integration. Therefore, the aim of this study was to address in more detail the enthesis as the thriphasic bone attachment of the ACL using a tissue engineering approach. To establish a tissue-engineered enthesis-like construct, triphasic scaffolds embroidered from poly(L-lactide-co-caprolactone) and polylactic acid functionalized with collagen foam were colonized with osteogenically differentiated human mesenchymal stromal cells (hMSCs) and lapine (L) ACL fibroblasts. These triphasic scaffolds with a bone-, a fibrocartilage transition- and a ligament phase were seeded directly after spheroid assembly or with 14 days precultured LACL fibroblast spheroids and 14 days osteogenically differentiated hMSCs spheroids (=longer preculture) and cultured for further 14 days. Cell survival was tested. Collagen type I and vimentin were immunolabeled and the content of DNA and sulfated glycosaminoglycan (sGAG) was quantified. The relative gene expression of tenascin C, type I and X collagens, Mohawk and Runx2 was analyzed. Compared to the LACL spheroids the hMSC spheroids adhered better to the scaffold surface with faster cell outgrowth on the fibers. Collagen type I and vimentin were mainly detected in the hMSCs colonizing the bone zone. The DNA content was generally higher in the bone (hMSCs) than in the ligament zones and after short spheroid preculture higher than after longer preculture whereas the sGAG content was greater after longer preculture for both cell types. The longer precultivated hMSCs expressed more type I collagen in comparison to those only shortly precultured before scaffold seeding. Type I collagen and tenascin C were higher expressed in scaffolds directly colonized with LACL compared to those seeded after longer spheroid preculture. The gene expression of ECM components and transcription factors depended on cell type and preculturing condition. Zonal colonization of triphasic scaffolds using the spheroid method is possible offering a novel approach for enthesis tissue engineering

The enthesis is a specialised zonal tissue interface between tendon and bone, essential for adequate force transmission and composed by four distinct zones, namely tendon, fibrocartilage, mineralized fibrocartilage and bone. Following injuries and surgical repair, the enthesis is often not reestablished and so far, traditionally used tissue substitutes have lacked to reproduce the complexity of the native tissue. In this work, we hypothesised that a collagen-based three-layer scaffold that mimic the composition of the enthesis, in combination with bioactive molecules, will enhance the functional regeneration of the enthesis. A three-layer sponge composed of a tendon-like layer (collagen I), a cartilage-like layer (collagen II) and a bone-like layer (collagen I and hydroxyapatite) was fabricated by an iterative layering freeze-drying technique. Scaffold porosity and structural continuity at the interfaces were assessed through SEM analysis. Bone-marrow derived stem cells (BMSCs) were seeded by syringe vacuum assisted technique on the scaffold. Scaffolds were cultured in basal media for 3 days before switching to differentiation media (chondrogenic, tenogenic and osteogenic). BMSCs metabolic activity, proliferation and viability were assessed by alamarBlue, PicoGreen and Live/Dead assays. At D21 the scaffolds were fixed, cryosectioned and Alizarin Red and Alcian Blue stainings were performed in order to evaluate BMSC differentiation towards osteogenic and chondrogenic lineage. The presence of collagen I and tenascin in the scaffolds was evaluated by immunofluorescence staining at D21 in order to assess tenogenic differentiation of BMSCs. Subsequently, the cartilage-like layer was functionalized with IGF-1, seeded with BMSCs and cultured in basal media up to D21. Structural continuity at the interfaces of the scaffolds was confirmed by SEM and scaffold porosity was assessed as >98%. The scaffolds supported cell proliferation and infiltration homogeneously throughout all the layers up to D21. Osteogenic differentiation of BMSC selectively in the bone-like layer was confirmed by Alizarin red staining in scaffolds cultured in basal and osteogenic media. Alcian blue staining revealed the presence of proteoglycans selectively in the cartilage-like layer in scaffolds cultured in chondrogenic media but not in basal media. Increased expression of the tenogenic markers collagen I and tenascin were observed in the tendon-like layer of scaffolds cultured in tenogenic but not in basal media for 21 days. The presence of IGF-1 increased osteogenic and chondrogenic differentiation of BMSCs, whereas no difference was observed for tenogenic differentiation. In conclusion, a 3-layer collagen sponge was successfully fabricated with distinct but integrated layers; the different collagen composition of the non-functionalized 3-layer sponge was able to regulate BMSC differentiation in a localized manner within the scaffold. The scaffold functionalization with IGF-1 accelerated chondrogenic and osteogenic BMSC differentiation. Overall, functionalization of the 3-layer scaffolds holds promising potential in enthesis regeneration

An established rabbit model was used to preliminarily investigate the effect of acellular triphase, namely bone-cartilage-tendon, scaffold (ATS) sandwiched with autologous bone mesenchymal stem cells (BMSCs) sheets on tendon-bone interface healing. Bone, fibrocartilage and tendon tissue were harvested from the rabbits and sectioned into a book-type scaffold. The scaffolds were decellularized and their characterization was presented. BMSCs were isolated and co-cultured with the scaffolds to verify their cytocompatibility. BMSCs sheets were fabricated and inserted into the book page of the scaffold to construct an autologous BMSCs-sheets/book-type ATS complex. The complex was implated in the right knee of rabbits which operated standard partial patellectomy for TBI regeneration using Imaging, histological and biomechanical examinations. The bone, fibrocartilage and tendon tissue were sectioned into a book-type scaffold before decellularization. Then we decellularized the above tissue and mostly preserved their microstructure and composition of the natural extracellular matrix, including collagen and proteoglycan. After the physicochemical and biological properties of the book-type ATS were evaluated, autologous BMSCs sheets were inserted into the book page of the scaffold to construct an autologous BMSCs-sheets/book-type ATS implants for TBI regeneration. In addition, the ATS has the advantages of non-toxicity, suitable for cell adhesion and growth as well as low immunogenicity while co-cultured with the BMSCs. At the same time, different scaffolds has the ability to induce the osteogenic, chondrogenic and tenogenic differentiation of BMSCs by immunofluorescence, reverse transcription-polymerase chain reaction and western blot analysis. To determine the efficacy of the tissue-engineered implants for TBI regeneration, we transplanted it into a rabbit patella-patellar tendon (PPT) injury model, and the rabbits were sacrificed at postoperative week 8 or 16 for the radiological, histological, and mechanical evaluation. Radiologically, Synchrotron radiation micro-computed tomography (SR-μCT) showed that BMSCs/ATS group significantly increased bone area, BV/TV, trabecular thickness and trabecular number at the healing interface as compared with other groups at postoperative week 8 or 16. Histologically, the BMSCs/ATS group showed more woven bone, and a more robust fibrocartilaginous junction with a characteristic matrix rich in proteoglycans was seen at the PPT healing interface in comparison with other groups after 8 weeks. At week 16, the healing interface in 3 groups displayed better remodeling with respect to postoperative week 8. Healing and remodeling at the PPT junction were almost complete, with a resemblance to a healthy BTI consisting of the characteristic 4 zones in all groups. At last, we used biomechanical test as functional parameters to evaluate the quality of tendon-bone healing. Biomechanical testing indicated that BMSCs/ATS group showed significantly higher failure load and stiffness than other groups at postoperative week 8 and 16. The complex composed of acellular triphase, namely bone-cartilage-tendon, scaffold (ATS) sandwiched with autologous bone mesenchymal stem cells (BMSCs) sheets can simulate the gradient structure of tendon-bone interface, inducing stem cell directional differentiation, so as to promote patella-patellar tendon interface healing effectively after injury

We used demineralised bone matrix (DBM) to augment re-attachment of tendon to a metal prosthesis in an in vivo ovine model of reconstruction of the extensor mechanism at the knee. We hypothesised that augmentation of the tendon-implant interface with DBM would enhance the functional and histological outcomes as compared with previously reported control reconstructions without DBM. Function was assessed at six and 12 weeks postoperatively, and histological examination was undertaken at 12 weeks. A significant increase of 23.5% was observed in functional weight-bearing at six weeks in the DBM-augmented group compared with non-augmented controls (p = 0.004). By 12 weeks augmentation with DBM resulted in regeneration of a more direct-type enthesis, with regions of fibrocartilage, mineralised fibrocartilage and bone. In the controls the interface was predominantly indirect, with the tendon attached to the bone graft-hydroxyapatite base plate by perforating collagen fibres

Articular cartilage implantation (ACI) and associated procedures (MACI = Matrix-assisted cartilage implantation) are now established treatments for osteochondral defects in the knee. The quality of repair in terms of histological appearance is frequently not known, whilst the correlation of histology results with functional outcomes remains undefined. Histological data of the quality of the repair tissue is sparse and a precise classification proved difficult. This was a single-centre, prospective study. Over 12 years (1998-2010) 406 patients that underwent articular cartilage implantation procedures at our institution (ACI = 170, MACI = 205) had biopsies taken at the 1-2 year interval, in order to assess whether these contained ‘hyaline-like’ cartilage, ‘mixed hyaline-like with fibrocartilage’, fibrocartilage or fibrous tissue alone. Histological sections of the biopsies were prepared and stained with haematoxylin, eosin and proteoglycan stains and viewed under polarised light. All biopsies were studied by a single histopathologist in a specialist, dedicated musculoskeletal laboratory. All patients were assessed by the Cincinnati, Bentley and Visual Analogue scores both pre-operatively and at the time of the review. The findings revealed that 56 patients healed with ‘hyaline-like’ cartilage (14.9%), 103 with ‘mixed’ (27.5%), 179 with fibrocartilage (47.7%) and 37 with fibrous tissue (9.9%). These findings showed that 42.4% of defects were filled with ‘hyaline-like’ or ‘mixed’ cartilage, with 70% of these achieving a ‘fair’ to ‘excellent’ functional outcome. This was also observed in the fibrocartilage group, where 72% achieved similar results. Predictably 89% of the patients that healed by fibrous tissue had a poor functional outcome. This study shows that 71% of patients whose osteochondral defects healed by either ‘hyaline-like’, ‘mixed’ or fibrocartilage experienced an improvement in the function. In contrast, only 11% of the patients whose defects filled with fibrous tissue, showed some functional improvement. Additionally, this data indicates the advantage of biopsies in assessing the overall results of cartilage implantation procedures

The enthesis is a specialised zonal tissue interface between tendon and bone, essential for adequate force transmission and composed by four distinct zones (tendon, fibrocartilage, mineralized fibrocartilage and bone). After injury, the native structure is often not re-established and a mechanically weaker fibrovascular scar is formed. Traditionally used monotherapies have failed to be effective, posing the need for multi-cargo localized delivery vehicles. We hypothesize that multilayer collagen-based scaffolds can serve as delivery vehicles for specific bioactive molecules with tenogenic, chondrogenic and osteogenic potential to enhance the functional regeneration of the enthesis. Three-layer scaffolds composed by a tendon-like layer of collagen type I, a cartilage-like layer of collagen type II and a bone-like layer of collagen type I and hydroxyapatite were fabricated by an iterative layering freeze-drying technique. The scaffolds were cross-linked with varying concentration of 4-arm polyethylene glycol (4s-PEG) and the biological and mechanical properties were assessed. Each layer was functionalized with platelet-derived growth factor, insulin growth factor, heparan sulfate or bone morphogenetic protein 7 and their tenogenic, chondrogenic and osteogenic potential on bone-marrow derived stem cells was investigated in vitro. Scaffolds cross-linked with 1 mM 4s-PEG showed 60% free amines reduction respect to non-cross-linked scaffolds, were stable in collagenase over 24 hours and had a compression modulus of 30 kPa. The bioactive molecules had a sustained release profile (approximately 50 ng/mL) over 5 days as a function of cross-linking. Preliminary in vitro studies confirmed the chondrogenic potential of heparin sulfate and insulin growth factor by the increase of proteoglycans

Summary Statement. Demineralised bone matrix augmented tendon-bone fixations in the animal model show less scar tissue and an enthesis morphology closer to the physiologic one which may lead to a more resistant repair construct. Introduction. Rotator cuff repair is one of the most common operative procedures in the shoulder. Yet despite its prevalence recurrent tear rates of up to 94% have been reported in the literature. High failure rates have been associated with tendon detachment from bone at the tendon – bone interface. Exogenous agents as biological strategies to augment tendon – bone healing in the shoulder represent a new area of focus to improve patient outcomes. Demineralised bone matrix (DBM) contains matrix bound proteins, exposed through acid demineralization step of DBM manufacture, and has long been recognised for its osteoinductive and osteoconductive properties. We hypothesised that DBM administered to the bone bed prior to the reattachment of the tendon, will upregulate healing and result in enhanced tissue morphology that more closely resembles that of a normal enthesis. An established ovine transosseous equivalent rotator cuff model was used. Methods. Following ethics approval, 10 adult wethers (18 months) were randomly allocated to control, n=4 (without DBM) or DBM, n=6 (DBM administered to bone bed) groups. The infraspinatus tendon was detached from its insertion and repaired in a transosseous equivalent fashion using PEEK suture anchors. In treatment animals 0.25cc of ovine DBM, previously prepared using a modified Urist protocol, was injected into two drill holes within the bony tendon footprint. Animals were culled at 4 weeks following surgery and processed for tissue histology and microcomputed tomography (μCT) endpoints. Results. No infection or tendon detachment following repair was noted in either group. 3D reconstructed images of μCT scans verified correct DBM and suture anchor placement. Histological images demonstrated distinct differences in tissue morphology between the two groups; however there was no evidence of the four – zoned structure characteristic of a healthy tendon bone insertion, in any specimens. In the control group specimens, the tendon midsubstance was highly disorganised with randomly arranged collagen fibres and diminutive areas of fibrocartilage. In the treatment group, large regions between tendon and bone were occupied by fibrocartilage. Within the fibrocartilage region, insertional collagen fibres appeared organised and chondrocytes were orientated in the direction of the insertional collagen fibres. Organised collagen fibre orientation within the tendon midsubstance was observed, though this was not consistent throughout all the specimens. DBM particles were resorbed and trabecular bone occupied the DBM holes. The PEEK anchors were all in direct contact with the ongrowing bone indicating good quality integration and fixation. Discussion. This study showed that DBM augmented tendon to bone repair leads to an upregulated cellular activity resulting in increased amounts of fibrocartilage between the repaired tendon and underlying bone. The upshot of this is an improved tissue organization which more closely resembles the morphology of the normal enthesis. Introduction of osteoinductive DBM at the tendon – bone interface during surgery may reduce failure rates associated with rotator cuff repair and improve clinical outcomes

Recent clinical studies on targeting nerve growth factor (NGF) in chronic low back pain and knee osteoarthritis have demonstrated efficient pain reduction in a short-term treatment regimen. However, the increased risk for the development of rapid progressive osteoarthritis at the required high drug dose remains a serious concern and prompts thorough analysis of the tissue distribution and role of NGF in degenerative musculoskeletal disorders. Here, we sought to investigate tissue distribution of NGF, its high affinity receptor TrkA and CD68-positive macrophages in human facet joint osteoarthritis of the lumbar spine. Facet joint specimens (n=10) were harvested by facetectomy from patients undergoing elective lumbar intervertebral spine fusion. Facet joint osteoarthritis and presence of synovitis was graded using preoperative magnetic resonance imaging. Tissue distribution of NGF, TrkA and CD68 was determined using immunohistochemistry. Tissue degradation was graded on safranin-O-stained tissue sections. Association between imaging parameters and tissue distribution was determined using Pearson correlation analysis. Synovitis was present in 6 cases and facet joints displayed moderate to severe radiological osteoarthritis (median Weishaupt grade; 2 [1.5–3]). NGF was expressed in 8 of 10 specimens. NGF was expressed in connective tissue, articular and fibrocartilage, but not bone tissue. Cartilaginous NGF expression was predominantly found in the extracellular matrix of superficial cartilage tissue with complete loss of proteoglycans, chondrocyte death and structural damage (fissures). Loss of cartilage proteoglycan staining alone did not display NGF immunoreactivitiy. NGF expression was not correlated with radiological osteoarthritis severity or presence of synovitis. NGF high affinity receptor TrkA was exclusively expressed in bone marrow tissues. Differential grades of bone marrow infiltration by CD68-positive macrophages were observed, yet these were not associated with NGF expression. Targeting NGF in chronic low back pain and/or facet joint osteoarthritis might affect pathomechanisms in cartilaginous tissues and NGF signalling in the bone marrow compartment

Abstract. Objectives. The scapholunate interosseous ligament (SLIL) has a unique C-shape following the arc of the scaphoid and lunate surfaces from distal dorsal around to distal volar. This ligament comprises of three subregions: dorsal, proximal and volar. The SLIL enthesis, a specialized region where this ligament attaches to the scaphoid and lunate, has not previously been studied despite its important mechanical function in the biomechanics of the wrist joint. This study therefore aims to compare the histomorphological differences between the SLIL subregions, including at their entheses. This study will examine the qualitative and quantitative differences between the three subregions, as well as between the scaphoid and lunate attachments. Methods. Twelve fresh-frozen human cadaveric wrists were dissected and the gross dimensions of each SLIL subregion measured. Subregions were then histologically processed for qualitative and quantitative morphological and compositional analyses, including quantification of enthesis calcified fibrocartilage (CF) area. Results. From the gross measurements taken, the dorsal subregion was the thickest. There were no significant differences in lengths and widths between the three subregions. Qualitatively, the dorsal and volar subregions had fibrocartilaginous entheses while the proximal subregion inserted into cortical bone via articular cartilage. Quantitatively, the dorsal subregion had significantly more CF than the volar subregion. There was no significant difference in the enthesis CF between scaphoid and lunate attachments in the three subregions. Conclusions. There are significant histomorphological differences between the SLIL subregions. The dorsal subregion has the largest amount of CF, which is consistent with the greater biomechanical force subjected to this subregion compared to the other subregions. This result confirms that the dorsal subregion is the strongest of the three subregions. The similar histomorphology of the ligament at the scaphoid and lunate entheses suggests that similar biomechanical forces are applied to both attachments. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

We prospectively studied the clinical, arthroscopic and histological results of collagen-covered autologous chondrocyte implantation (ACI-C) in patients with symptomatic osteochondritis dissecans of the knee. The study included 37 patients who were evaluated at a mean follow-up of 4.08 years. Clinical results showed a mean improvement in the modified Cincinnati score from 46.1 to 68.4. Excellent and good clinical results were seen in 82.1% of those with juvenile-onset osteochondritis dissecans but in only 44.4% of those with adult-onset disease. Arthroscopy at one year revealed International Cartilage Repair Society grades of 1 or 2 in 21 of 24 patients (87.5%). Of 23 biopsies, 11 (47.8%) showed either a hyaline-like or a mixture of hyaline-like and fibrocartilage, 12 (52.2%) showed fibrocartilage. The age at the time of ACI-C determined the clinical outcome for juvenile-onset disease (p = 0.05), whereas the size of the defect was the major determinant of outcome in adult-onset disease (p = 0.01)

1. A general picture of the histological state of the bone-cement junction, up to seven years after implantation, is presented as a result of the study of twenty-three human specimens. 2. The transmission of load from cement to bone occurs at isolated points through the medium of newly formed fibrocartilage. 3. It is clear that this fibrocartilage has been produced in response to mechanical pressure on fibrous tissue which has undergone compression between cement and underlying bone. 4. Direct contact exists between the surface of the cement and the newly formed fibrocartilage at these sites of load transmission. 5. Load-bearing fibrocartilage frequently shows areas of ossification extending into it from the underlying bone. 6. Where soft tissues in contact with cement are too thick or too delicate for load transmission a thin layer of giant-cell cytoplasm coats the cement surface. 7. No collections of giant cells to form granulomatous or caseating areas have been seen. 8. Fat storage, indicating the absence of chemical irritation, can occur within ten microns of the cement surface

Research in to tendon-bone healing techniques focus on increasing bone growth at the interface such as cell or growth factor (e.g. BMP-2) augmentation. Demineralised bone matrix (DBM) is osseoinductive and is in use clinically. Hypothesis: DBM augmentation of a healing tendon-bone interface will result in improved function at 3, 6, 9 and 12 weeks, and a morphology that more closely resembles that of a normal enthesis at 12 weeks. Materials and methods: An ovine patellar tendon model was used. 19 skeletally mature ewes were allocated to the control group or DBM group. In both groups the patellar tendon was detached, and following tibial tubercle osteotomy, was re-attached using 3 suture anchors. In the DBM group a piece of DBM was placed between the tendon and bone. 2 animals were sacrificed at 6 weeks and 6 animals at 12 weeks. Animals underwent force plate analysis at 3, 6, 9 and 12 weeks. The tendon-bone interface length which was fibrous or fibrocartilaginous, and the area of fibrocartilage, mineralised fibrocartilage and new bone was quantified. Results: 3 control group animals (33%) failed within 6 weeks. None failed in the DBM group. The DBM group was significantly better than the control at all time points (p< 0.05). DBM produced a significantly more fibrocartilaginous enthesis than the control group (p< 0.05). Controls were significantly more fibrous than the DBM group (p< 0.05). DBM produced significantly more fibrocartilage (p< 0.05), and mineralised fibrocartilage (p< 0.05). Discussion: 33% of the control group failed within 6 weeks, whilst no failures were observed in the DBM group. DBM animals mobilised earlier and had significantly better function at all time points. Histologically, the DBM group showed a more mature direct type enthesis at earlier time points. Conclusion: DBM augmentation of a healing tendon-bone interface enhances functional and morphological recovery at earlier time points

The clinical diagnosis of distal radioulnar joint (DRUJ) instability remains challenging. The current diagnostic gold standard is a dynamic computerized topography (CT) scan. This investigation compares the affected and normal wrists in multiple static positions of forearm rotation.. However, its accuracy has been questioned, as the wrist is unloaded and not placed under stress. This may fail to capture DRUJ instability that does not result in static malalignment between the ulnar head and sigmoid notch. The purpose of this biomechanical study was to evaluate the effectiveness of both dynamic and stress CT scans in detecting DRUJ instability. A customized DRUJ arthrometer was designed that allows for both static positioning, as well as dorsal and volar loading at the DRUJ in various degrees of forearm rotation. Ten fresh frozen cadavers were prepared and mounted in the apparatus. CT scans were performed both in the unloaded condition (dynamic CT) and with each arm subjected to a standardized 50N volar and dorsal force (stress CT) in neutral and maximum pronation/ supination. The TFCC (triangular fibrocartilage complex)was then sectioned peripherally to simulate DRUJ instability and the methodology was repeated. CT scans were then evaluated for displacement using the radioulnar ratio method. When calculating the radioulnar ratio for intact wrists using the dynamic CT technique, values were 0.50, 0.64, 0.34 for neutral, pronation and supination, respectively. When the TFCC was sectioned and protocol repeated, the values for the simulated unstable wrist for dynamic CT were 0.54, 0.62, 0.34 for neutral, pronation and supination, respectively. There was no statistically significant difference between the intact and sectioned states for any position of forearm rotation using dynamic CT. Usingstress CT, mean radioulnar ratios for the intact specimens were calculated to be 0.44, 0.36 and 0.31 for neutral, pronation and supination, respectively. After sectioning the TFCC, the radioulnar ratios increased to 0.61, 0.39 and 0.46 for neutral, pronation and supination. There was a statistically significant difference between intact and simulated-unstable wrists in supination (p = 0.002) and in neutral (p=0.003). The radioulnar ratio values used to measure DRUJ translation for dynamic CT scans were unable to detect a statistically significant difference between stable and simulated unstable wrists. This was true for all positions of forearm rotation. However, when a standard load was placed across the DRUJ, statically significant changes in the radioulnar ratio were seen in neutral and supination between stable and simulated unstable wrists. This discrepancy challenges the current gold standard of dynamic CT in its ability to accurately diagnosis DRUJ instability. It also introduces stress CT as a possible solution for diagnosing DRUJ instability from peripheral TFCC lesions

Background. Based on decellularisation and cleaning processes of trabecular bone and fibrocartilage, an osteochondral allograft has been developed. Material. The chemical process, established thanks to bone and fibrocartilage data, included an efficient viroinactivation step. The raw material was a tibial plateau collected during knee arthroplasty, cut in cylinders strictly selected (>2mm cartilage height and total height between 10 and 16mm). The grafts were freeze-dried and gamma sterilised. Methods. Decellularisation and structure integrity were validated based on histological analysis, before and after treatment. Mesenchymal Stem Cells (MSC) proliferation in contact with the graft was evaluated to validate the biocompatibility. Biomechanics of the cartilage was studied to determine the compressive resistance before and after treatment. Proof of concept has been completed on femoral condyles in a rabbit model: osteochondral allografts of rabbit were prepared from femoral condyles, processed like human allografts and implanted in 6 femoral condyle defects of 4mm diameter and compared to 3 sham-operated sites. Rabbits were sacrificed at 12 weeks. Macroscopic evaluation and histological stainings were carried out to determine bone and cartilage reconstruction. Results. The stainings of processed grafts showed decellularisation, cleaning of bone, porosity of cartilage tissue, decrease in the aggrecan rate and preservation of type II collagen. MSC proliferated inside the trabecular bone and spread at the surface of the cartilage tissue after 3 weeks. Compressive resistance of cartilage before and after processing was similar to literature. Osteochondral rabbit defects were filled with bone and cartilage tissue, with total integration of bone and cartilage repair observed in two ways: cells spreading from lateral cartilage and MSC diffusing from subchondral plate. Conclusions. The decellularised biocompatible osteochondral allograft enhanced cartilage repair in an animal model. Two clinical trials are ongoing in talus and knee osteochondral lesions

Objective. To investigate the histological and immunohistochemical characteristics of revised and failed MACI repair tissues. Methods. We examined the matrix profiles of repair biopsies taken from revised and clinically failed MACI cases by semi-quantitative immunohistochemical study using antibodies specific to aggrecan, collagens I, II, III, VI, and IX, Sox-9, Ki-67 and MMP-13. We also stiffness tested an intact clinically failed repair site. Results. Histologically, the majority of these biopsies (n=39) were hyaline-like (HLC) and fibrocartilage (FC) in both the revised (30% and 38% respectively) and failed (34% and 22% respectively) cases. Compositionally, more revised cases were positive for aggrecan, collagens VI and IX, and Ki67 compared to failed cases, but not quantitatively different (P>0.05). More HLC biopsies were positive for aggrecan and collagen II (compared to the FC group), with diffuse and often colocalized matrix distribution. The majority of HLC biopsies stained positive for Sox-9, whereas FC cases were negative. Most (75%) FC biopsies were positive for Ki-67, compared to the HLC group with 25%. MMP-13 was negative in all biopsies. Qualitatively, reduced collagen II and IX, and increased Ki67 production was noted in FC biopsies (P<0.05). An intact repair site showed FC with 30% greater stiffness in the inferior portion compared to the superior, with an associated proteoglycan content increase. Conclusions. Revised and failed biopsies display predominantly fibrocartilage and hyaline-like cartilage and are histologically dissimilar to healthy cartilage, but do not differ in composition. Hyaline-like repairs show lower proliferation but improved matrix to fibrocartilage repairs. Our study furthers knowledge into failed and revised cartilage repair by MACI

Background. Re-attachment of tendon to bone is challenging with surgical repair failing in up to 90% of cases. Poor biological healing is common and characterised by the formation of weak scar tissue. Previous work has demonstrated that decellularised allogenic demineralised bone matrix (DBM) regenerates a physiologic enthesis. Xenografts offer a more cost-effective option but concerns over their immunogenicity have been raised. We hypothesised that augmentation of a healing tendon-bone interface with DBM incorporated with autologous mesenchymal stem cells (MSCs) would result in improved function, and restoration of the native enthesis, with no difference between xenogenic and allogenic scaffolds. Methods. Using an ovine model of tendon-bone retraction the patellar tendon was detached and a complete distal tendon defect measuring 1 cm was created. Suture anchors were used to reattach the shortened tendon and xenogenic DBM + MSCs (n=5) and allogenic DBM + MSCs (n=5) were used to bridge the defect. Functional recovery was assessed every 3 weeks and DBM incorporation into the tendon and its effect on enthesis regeneration was measured using histomorphometry. Results. By 12 weeks, DBM augmentation resulted in significantly improved functional weight bearing with no failures in either group. Compared to xenogenic DBM, allogenic DBM was associated with significantly higher functional weight bearing at 6 (P=0.047), 9 (P=0.028) and 12 weeks (P=0.009). This was accompanied by a more direct type of enthesis characterised by significantly more fibrocartilage and mineralised fibrocartilage. Xenograft was also associated with an immunogenic reaction despite preoperative decellularisation. Conclusion. This study shows that DBM enhances tendon-bone healing and may reduce the high failure rates associated with surgery. An immunogenic reaction, and inferior biomechanical and histological results were also associated with the use of xenograft. Allogenic DBM with autologous MSCs may be a suitable scaffold for the enhancement of tendon-bone healing in the clinical setting. Disclosures. Funded by IKC PoC grant awarded by the University of Leeds. Ethical approval. Granted by the study institution (University College London)

Introduction. Prospective comparative study to evaluate the efficacy of the ultrasound diagnosis vs MRI in rupture of the Triangular fibrocartilage with arthroscopic confirmation. Material and methods. 55 patients presenting clinical wrist pain were studied from January’2004 untill september 2006. Our patient selection was composed by 30 men and 25 women, and the age range was 17 to 70 years old. 40 were Right-handed and 15 Left-Handed. Patients presented wrist pain related to several disorders. Our protocol included Sonography with a 11–MHz linear array probe using real-time compound spatial imaging and 1T-MRI studies. Wrist arthroscopy was performed in all of them. Results. 67 % of our patients presented Triangular fibrocartilage rupture at arthroscopy. The distribution of our patients related to the complementary tests was:. - Arthroscopy (+) 37 cases out of 50 (64%). - Ultrasound (+) 21 out of 37 (+ Art)). - MRI (+) 22 out of 37 (+ Art). According to this results we can easily calculate the sensibility/specificity and PPV/PNV of both tests:. - Ultrasound Sensibility/Specificity: 58,3 %/36,8 %. - MRI Sensibility/Specificity: 61 %/47 %. - Ultrasound PPV/PNV: 58 %/31,8 %. - MRI PPV/PNV: 68 %/37 %. Conclusions. Due to the results we obtained in our study, we can consider ultrasound as sensible and specific as MRI at diagnosis for the rupture of the Triangular fibrocartilage. In our opinion we conclude that neither MRI nor ultrasound results should be considered satisfactory for a proper diagnosis. This could be sorted out by the use of more resolutive MRI and ultrasound equipments

Ulnar shortening osteotomy (USO) is a procedure performed to alleviate ulnar sided wrist pain caused by ulnar impaction syndrome (UIS) and/or triangular fibrocartilage complex (TFCC) injury. Presently, non-union rates for ulnar shortening osteotomy is quoted to be 0–18% in the literature. However, there is a dearth of literature on the effect of site of osteotomy and plate placement on the rate of complications like a delayed union, symptomatic hardware and need for second surgery for hardware removal. In this study, we performed a multi-centered institutional review of ulnar shortening osteotomies performed, focusing on plate placement (volar vs. dorsal) and osteotomy site (distal vs. proximal) and determining if it plays a role in reducing complications. This study was a multi-centered retrospective chart review. All radiographs and charts for patients that have received USO for UIS or TFCC injury between 2013 and 2017 from hand and wrist fellowship-trained surgeons in Calgary, Alberta and Winnipeg, Manitoba were examined. Basic patient demographics including age, sex, past medical history, and smoking history were recorded. Postoperative complications such as delayed union, non-union, infection, chronic regional pain syndrome, hardware irritation requiring removal were evaluated with a two-year follow-up period. Osteotomy sites were analyzed based on the location in relation to the entire length of the ulna on forearm radiographs. Surgical techniques including volar vs. dorsal plating, oblique vs. transverse osteotomy cuts, and plate type were documented. Continuous variables of interest were summarized as mean or medians with standard deviation or inter-quartile range as appropriate. Differences in baseline characteristics were determined by t-test or one-way ANOVA for continuous variables and chi-square or Fischer exact test for dichotomous variables. All analyses were conducted using SPSS V24.0 (Chicago, IL, USA). All statistical tests were considered significant if p < 0.05. Between 2013–2017 there were 117 ulnar shortening osteotomies performed. The average age of patients was 46.2 ± 16.2, with 62.4% being female. The mean pre-operative ulnar variance was +3.89 ± 2.17 mm and post-operative ulnar variance was −1.90 ± 1.80 mm. 84.6% of the plates were placed on the volar aspect of the ulna and 14.5% were placed on the dorsal aspect. An oblique osteotomy was made 99.1% of the time. In measuring osteotomy placement, the average placement was made in the distal 1/3 of the ulna. Overall, there was a 40% complication rate. Hardware irritation requiring removal encompassed 23%, non-union 14%, and wound infection covered 0.8%. When comparing dorsal vs volar plating, there was no statistically significant difference for non-union or hardware removal. Similarly, in evaluating osteotomy level, there was no statistical difference between proximal vs distal osteotomy for non-union and hardware removal. In this multi-centered retrospective review of ulnar shortening osteotomies, we found that there was an overall complication rate of 40%. There was no statistically significant difference in complication rates between dorsal vs volar plate placement or proximal vs distal osteotomy sites. Further studies examining other potential risk factors in lowering the complication rate would be beneficial

The purpose of this study was to evaluate treatment results following arthroscopic triangular fibrocartilage complex (TFCC) debridement for recalcitrant ulnar wrist pain. According to the treatment algorithm, 66 patients (36 men and 30 women with a mean age of 38.1 years (15 to 67)) with recalcitrant ulnar wrist pain were allocated to undergo ulnar shortening osteotomy (USO; n = 24), arthroscopic TFCC repair (n = 15), arthroscopic TFCC debridement (n = 14) or prolonged conservative treatment (n = 13). The mean follow-up was 36.0 months (15 to 54). Significant differences in Hand20 score at 18 months were evident between the USO group and TFCC debridement group (p = 0.003), and between the TFCC repair group and TFCC debridement group (p = 0.029). Within-group comparisons showed that Hand20 score at five months or later and pain score at two months or later were significantly decreased in the USO/TFCC repair groups. In contrast, scores in the TFCC debridement/conservative groups did not decrease significantly. Grip strength at 18 months was significantly improved in the USO/TFCC repair groups, but not in the TFCC debridement/conservative groups. TFCC debridement shows little benefit on the clinical course of recalcitrant ulnar wrist pain even after excluding patients with ulnocarpal abutment or TFCC detachment from the fovea from the indications for arthroscopic TFCC debridement. Cite this article: Bone Joint J 2013;95-B:1687–96

The goal of surgery for osteochondral lesions is to regenerate the damaged cartilage with ideally hyaline cartilage. The current gold standard treatment is bone marrow stimulation (BMS) by microfracture. In reality however BMS typically results in the generation of fibrocartilage. Orthobiologics including bone marrow aspirate, platelet rich plasma and hyaluronic acid products have been shown to promote cartilage healing and potentially increase the formation of hyaline cartilage in treated lesions. However the role of these products, the timing of their administration and frequency of application are still not clearly defined and their routine use is still not recommended. These issues and future directions for research and future clinical application will be discussed

Introduction: Articular cartilage has compressive stiffness determined primarily by the matrix and it is quite characteristic and distinct from that of degenerative articular cartilage or regenerative fibrocartilage.Alterations that are evident when articular cartilage begins to degenerate include a decrease in proteoglycan content and water content and resultant reduction in stiffness. Regenerative fibrocartilage has greatly reduced stiffness with functional implications. Identification of cartilaginous stiffness for various sites of normal articular cartilage in the knee is important to enable comparison measures of suspected degenerative cartilage and regenerative articular cartilage either hyaline, fibrocartilage or mixed. Aim: To map the biomechanical properties of normal human articular cartilage in vivo using the Artscan 1000 arthroscopic cartilage stiffness tester (Artscan Oy, Finland). Method: Over a period of 12 months, 94 patients (aged 15 to 69 years) undergoing a knee arthroscopy consented to having their normal articular surfaces evaluated biomechanically for stiffness. Cartilage stiffness (N) was defined by the mean indenter force at each site where the applied force on the measurement rod equalled 10 ±1.5N. `Results: Medial femoral condyle stiffness (mean ± SD; 3.71 ± 1.28N) was greater than all other sites and was significantly greater than mean values obtained for proximal, distal and lateral trochlea (1.87 ± 0.91, 2.44 ±1.02 and 2.69 ±1.52N, respectively); medial (1.71 ± 0.70N) and lateral patella (2.18 ± 1.03N); and medial and lateral tibial plateaux for all subjects (2.33 ± 1.26 and 2.27 ± 1.19N, respectively; p < 0.05). There were no significant differences between sexes for each site. There was no trend for cartilage stiffness to be lower in patients over forty compared with younger patients for both sexes, for all sites. There was however, statistically significant less stiffness of the distal trochlea for females under 40 when compared with that of females older than 40 years. The clinical significance of this is under review. Conclusion: Further research involving the characterisation of cartilage stiffness in pathological situations and evaluation of stiffness following articular cartilage repair is now possible