Kirschner wires are commonly used in paediatric fractures, however, the requirement for removal and the possibility of pin site infection provides opportunity for the development of new techniques that eliminate these drawbacks. Bioabsorbable pins that remain in situ and allow definitive closure of skin at the time of insertion could provide such advantages. Three concurrent studies were performed to assess the viability of bioabsorbable pins across the growth plate. (1) An epidemiological study to identify Kirschner wire infection rates. (2) A mechanical assessment of a bioabsorbable pin compared to Kirschner wires in a simulated supracondylar fracture. (3) The insertion of the implants across the physis of sheep to assess effects of the bioabsorbable implant on the growth plate via macroscopic, pathohistological and micro-CT analysis. An infection rate of 8.4% was found, with a deep infection rate of 0.4%. Mechanically the pins demonstrated comparable resistance to extension forces (p=) but slightly inferior resistance to rotation (p=). The in vivo component showed that at 6 months: there was no leg length discrepancy (p=0.6), with micro-CT evidence of normal physeal growth without tethering, and comparable physeal width (p=0.3). These studies combine to suggest that bioabsorbable pins do not represent a threat to the growth plate and may be considered for physeal fracture fixation

The previous bioabsorbable plates have had several issues with regard to clinical usage for fractures. The aims of this study were to demonstrate the clinical results of novel bioabsorbable plates made of hydroxyapatite/poly-L-lactide and titanium plates for metacarpal fractures and to compare mechanical properties of them in a fracture model. The subjects were 33 metacarpal diaphyseal fractures of 27 consecutive patients treated with bioabsorbable plates. The mean age was 35.8 (17–78), 22 male and 5 female was included. The mean follow up period was 7.4months (2–14). All cases achieved bone union, and there were no complication especially for aseptic swelling etc. Furthermore, we compared the mechanical properties of bioabsorbable and titanium plates. There were no significant differences in 6 month postoperative clinical results including total range of active motion and % of the contralateral grip strength between patients receiving bioabsorbable and titanium plates. The bending strength and stiffness of one-third tubular bioabsorbable plate constructs were comparable with those of titanium plates for 1.5mm screws, and those of semi-tubular bioabsorbable plates were comparable with those of titanium plates for 2.0mm screws. The torsional strength of semi-tubular bioabsorbable plates was significantly greater than that of titanium plates for 2.0mm screws

Aim. Excision of chronic osteomyelitis (cOM) creates a dead space which must be managed to avoid early recurrence of infection. Systemic antimicrobials cannot penetrate this space in high concentration so local therapy has become an attractive adjunct to surgery. This study presents the mid- long-term results of local therapy with gentamicin in a bioabsorbable ceramic carrier. Method. A prospective series of 100 patients with Cierny & Mader Types III and IV cOM, affecting 105 bones, were treated with a single stage procedure, including debridement, deep tissue sampling, local and systemic antimicrobials, stabilization and immediate skin closure. cOM was confirmed with strict diagnostic criteria. Patients were followed up for a mean of 6.05 years (range 4.2–8.4 years). Results. At final follow-up, 6 patients had evidence of recurrent infection (94% infection-free). 3 infections recurred in the first year, with 2 in the second year and one at 4.5 years after surgery. Recurrence was not dependent on host physiological class (1/20 Class A; 5% vs 5/80 Class B; 6.25%. p=0.833). Nor was it related to aetiology of the infection, microbial culture or the presence of an infected non-union before surgery (1/10 with non-union; 10% vs 5/90 without non-union; 5.6%. p=0.57). Organisms which demonstrated intermediate or high-grade resistance to gentamicin were more likely in polymicrobial infections (9/21; 42.8%) compared to single isolate osteomyelitis (7/79; 8.9%)(p<0.001). However, recurrence was not more frequent when a resistant organism was present (1/16; 6.25% for resistant cases vs 5/84; 5.95% in sensitive culture infection) (p=0.96). Conclusions. This study shows that the single stage protocol, including a high delivery local antibiotic ceramic, was effective over several years. The method can be applied to a wide range of patients, including those with significant comorbidities and infected non-union

Introduction: The introduction of bioabsorbable materials has improved the ability to offer a simple, fast and friendly user solution, to specific meniscal tears. The technique of meniscal suture with bioabsorbable tacks is associated with lower morbidity and lower complication rate. Methods: Between 1997 and 2004, 14 patients underwent arthroscopic all-inside meniscus repair. We used Biofix bioabsorbable tacks fixation technique. Fourteen patients were followed-up: 11 males and 3 females. Their mean age was ~23 years (range 16–34). Follow-up average ~35 (range 6–72) months. Sport injuries were the main cause of meniscal tears (60%). Other causes included: work accidents (20%) and military accidents (20%). All the tears were located in red-on-red and red-on-white area. The mean length of tear was 9.6 mm. we used in average 2.5 tacks per meniscus tear. Furthermore, 4 patients had an associated ACL tear. Results: The evaluation was based on Lisholm score. The results were excellent in 10 patients (71%), good in 1 patient (7%), fair in 2 patients (15%) and poor in 1 patient (7%). One patient suffered from transitory tender point on the medial aspect due to a protruded tack. One patient needed a menisectomy due to unresolved symptoms. One patient underwent ACL reconstruction. Conclusion: This technique is an easy and reproducible procedure as compared to the classical meniscal suture techniques. It seems to be of a lower complication rate and further studies are needed to establish any associated morbidity

Bioabsorbable metals hold a lot of potential as orthopaedic implant materials. Three metal families are currently being investigated: iron (Fe), magnesium (Mg) and zinc (Zn). Currently, however, biodegradation of such implants is poorly predictable. We thus used Direct Metal Printing to additively manufacture porous implants of a standardized bone-mimetic design and evaluated their mechanical properties and degradation behaviour, respectively, under in vivo-like conditions. Atomized powder was manufactured to porous implants of repetitive diamond unit cells, using a ProX DMP 320 (Layerwise, Belgium) or a custom-modified ReaLizer SLM50 metal printer. Degradation behaviour was characterized under static and dynamic conditions in a custom-built bioreactor system (37ºC, 5% CO. 2. and 20% O. 2. ) for up of 28 days. Implants were characterized by micro-CT before and after in vivo-like degradation. Mechanical characterization (according to ISO 13314: 2011) was performed on an Instron machine (10kN load cell) at different immersion times in simulated body fluid (r-SBF). Morphology and composition of degradation products were analysed (SEM, JSM-IT100, JEOL). Topographically identical titanium (Ti-6Al-4V, Ti64) specimen served as reference. Micro-CT analyses confirmed average strut sizes (420 ± 4 μm), and porosity (64%), to be close to design values. After 28 days of in vivo-like degradation, scaffolds were macroscopically covered by degradation products in an alloy-specific manner. Weight loss after cleaning also varied alloy-specifically, as did the change in pH value of the r-SBF. Corrosion time-dependent changes in Young's moduli from 1200 to 800 MPa for Mg, 1000 to 700 MPa for Zn and 48-8 MPa for iron were statistically significant. In summary, DMP allows to accurately control interconnectivity and topology of implants from all three families and micro-structured design holds potential to optimize their degradation speed. This first systematic report sheds light into how design influences degradation behaviour under in vivo-like conditions to help developing new standards for future medical device evaluation

Background. Successful use of bioabsorbable anchors for capsulolabral and rotator cuff repair is well documented. The bioknotless anchor (DePuy mitek) has demonstrated reliable fixation of these pathologies. However, this poly (L-lactide) polymer has recently demonstrated some similar complications to those documented for the earlier polyglycolic acid implants; namely synovitis and chondral damage with osteolysis. We report three cases with osteolysis and chondral damage associated with bioknotless anchors. Methods. A prospective record of shoulder arthroscopy is maintained by the senior author. From this, three patients with post-operative complications of arthropathy and osteolysis, following bioabsorbable anchor repair of capsulolabral lesions were identified. A retrospective review of case notes, radiographs, operative records and intraoperative video and photographic material was undertaken. Results. All patients had acceptable initial progress of rehabilitation. At 12-15 months, recurrence of symptoms promoted further radiological investigation and where the patient consented, repeat arthroscopy. In all cases advanced arthropathy was noted. Conclusion. It is likely that the use of knotless bioabsorbable anchors may promote advanced arthropathy. Initial loss of fixation and early pullout of the anchors may allow synovial contact with anchor material promoting hydrolysis and early arthropathy

To evaluate the functional outcome after anterior cruciate ligament reconstruction using bioabsorbable femoral cross-pin fixation. 30 patients with chronic anterior cruciate ligament deficiency, treated by arthroscopic reconstruction using hamstring tendon autograft have been reviewed. 3.3mm bioabsorbable (polylactic acid) cross-pins (Rigidfix, Ethicon) were used for graft fixation in the femoral tunnel. Outcome assessment was performed using Lysholm score,Tegner activity level, KT-1000 Arthrometer laxity measurements, single legged hop test and SF-36 evaluation. There were 20 male and 10 female patients with an age between 17 and 45 years(mean 25.1 yrs).The mean follow up was 20.3 months (range12–29 months). The mean Tegner score was 5.5 with a range of 3 to 7. Lysholm scores averaged 88.27 with a range of 74 to 100. The range of movement in the operated knee was comparable to that in normal knee. The single legged hop was 93.4% of the unoperated side. The average KT-1000 side to side difference was 3.2 mm using a 30 lb force and 3.5mm on manual maximal load. Biabsorbable femoral cross-pin fixation offers a viable and safe method of graft fixation in anterior cruciate ligament reconstruction and yeilds a satisfactory functional outcome

Aims: This presentation deals with our clinical experience based on experimental studies when using bioabsorbable fixation devices in bone, joint and ligament surgery. These devices were clinically introduced by us in the treatment of fractures in the extremities in the mid – 1980’s. Our own list of publications consists of 1137 publications since 1978 including, 26 academic dissertations. Before and during our clinical studies over 6500 animals were operated on in our experimental studies. Macroscopic, radiographic, microradiographic, histologic, histomorphometric and fluorochrome studies were done. Methods: The strength, strength retention, degradation, bone changes, healing of fractures, and injuries, and the fixation properties of the implants were investigated in vivo. Results: In Kuopio (814) and in Helsinki (3555) 4369 operations were done using bioabsorbable self-reinforced (SR) fixation implants mainly polyglycolide or poly-L-lactide during 1984–2001. In Helsinki there were 2766 trauma operations and 789 orthopaedic operations. The postoperative clinical course was uneventful in 82% of the patients. The complications included wound infection in 4.0%, failure of fixation in 3.9%, a non-infectious foreign-body reaction (sinus) in 1.9% (with SR-polyglycolide implants) but not with SR-polylactide implants. Conclusions: Due to the biodegradibility of the devices, implant removal procedures were avoided

Introduction: To report the results of quadrupled hamstring tendon autograft anterior cruciate ligament reconstruction with bioabsorbable Rigidfix fixation for both femoral and tibial tunnels. Methods: ninety one patients were retrospectively identified by notes review as having undergone quadrupled hamstring tendon auto graft anterior cruciate ligament reconstruction with Bioabsorbable Rigidfix fixation with a minimum 1 year follow-up[range12 to 34 months] To our knowledge there has been no published results with Rigidfix device used as a method of fixation at both femoral and tibial tunnels. Results: Data were collected on 91 knees in 91 patients (100 %) at an average 13 months (range, 12 to 34) after surgery. They were all asked to fill in a subjective quetionaire. Seventy eight patients returned for clinical evaluation (85.7 % return) and subjective questionnaire was comleted by 78 patients (85.7 %). The KT-2000 Arthrometer, mean side-to-side difference for manual maximum displacement was 1 mm (range, 0 to 3). Anterior compliance index mean side-to-side difference was1 (range −1 to 3), Quadriceps active displacement tests mean side-to-side difference was.5 [range −1 to 2]. The mean International Knee Documentation Committee knee score was 89 (range, 33.3 to 100). Conclusions: Quadrupled hamstring tendon auto graft anterior cruciate ligament reconstruction with Bioabsorbable Rigidfix fixation is comparable with other methods of anterior cruciate ligament reconstruction in terms of patient satisfaction, knee stability, and function

Purpose. To evaluate the results of quadrupled hamstring tendon autograft anterior cruciate ligament reconstruction with four fold Hamstring Tendon Graft using Transfix and Bioabsorbable Interference Screw Fixation. Study Design. Retrospective review. Methods. Sixty-five patients (66 knees) were retrospectively identified by chart review as having undergone quadrupled hamstring tendon autograft anterior cruciate ligament reconstruction, with four fold Hamstring Tendon Graft, using Transfix and Bioabsorbable Interference Screw Fixation. All patients underwent a minimum two-year follow-up. Results. Data were collected on 48 knees in 47 patients (73%) at an average 30.2 months (range 24 to 43) after surgery. Thirty-six patients (37 knees) returned for clinical evaluation (56% return) and subjective follow-up only was obtained in 11 patients (17%). The mean Lysolm knee score was 91 (range, 45 to 98), with a mean of 97 for the uninvolved knee. The mean Tegner activity score was 5.7 (range 3 to 7). The KT-1000 arthrometer mean side-to-side difference for manual maximum displacement was 2.03 mm (range -1 to 8). The mean International Knee Documentation Committee knee score was 83 (range 47 to 100). Patients who underwent associated partial meniscectomy or meniscal repair had significantly lower International Knee Documentation Committee scores than patients without associated procedures (P < 0.01). Conclusions. Quadrupled hamstring tendon autograft anterior cruciate ligament reconstruction with bioabsorbable interference screw fixation is comparable with other methods of anterior cruciate ligament reconstruction in terms of patient satisfaction, knee stability, and function

Introduction. The treatment of chronic osteomyelitis involves a debridement of affected non-viable tissue and the use of antibiotics. Where surgery leaves a cavity, dead space management is practised with antibiotic impregnated cement. These depots of local antibiotics are variable in elution properties and need removal. We review the use of bioabsorbable synthetic calcium sulphate as a carrier of gentamicin and as an adjunct in treating intramedullary osteomyelitis. Methods. A retrospective review of cases treated consecutively from 2006 to 2010 was undertaken. Variables recorded included aetiology, previous interventions, diagnostic criteria, radiological features, serology and microbiology. The Cierney-Mader system was used to classify. Treatment involved removal of implants (if any), intramedullary debridement and local resection (if needed), lavage and instillation of the gentamicin carrier, supplemented with systemic antibiotics. Follow-up involved a survival analysis to time to recurrence, clinical and functional assessment (AOFAS-Ankle/IOWA knee/Oxford Hip) and general health outcome (SF36). Results. There were 31 patients (22 male, 9 female). The mean age was 47 years (20–67). Twenty-five cases were post-surgery (6 open fractures) and 6 were haematogenous in origin. The median duration of osteomyelitis was 1.6yrs. The bones affected were 42% femur, 45% tibia, 3% radius and 10% humerus. 11 cases had diffuse as well as intramedullary involvement. 9 cases underwent segment resection and bone transport. We identified Staph. Aureus in 16 and Coag. Neg. Staph. in 6 cases. The median follow-up was 1.7 years (0.5–5.6). The median scores attained were: AOFAS-78, DASH-32, IOWA-71, Oxford-32. There were two recurrences. Discussion. Dead space management of intramedullary infections is difficult. We describe a method for delivery of local antibiotics and provide early evidence to its efficacy. The treatment success to date is 93%. Conclusion. Bioabsorbable carriers of antibiotics are efficacious adjuncts to surgical treatment of intramedullary osteomyelitis

Innominate Osteotomy first described by Salter is one of the commonest procedures performed for treatment of Developmental Dysplasia of the Hip (DDH) in children. We recently described a less invasive technique for Innominate Osteotomy, which significantly reduces the operation time without compromising outcome (J Pediatr Orthop B. 2010 Jul;19(4):318–22). As part of the evolution of this procedure we now routinely use bioabsorbable pins (INION OTPS PIN, made from co-polymers of L-lactic acid, D-lactic acid and trimethylene carbonate) instead of K-wires to secure the graft. We prospectively followed-up 120 consecutive cases done using bioabsorbale pins over a 2 year period. The surgical technique was as described in our less invasive innominate osteotomy paper. Average age at surgery was 24 months (18–52) with mean follow-up period of 15 months (6–24 months). The mean preoperative acetabular index was 36.2. o. Our results show a mean acetabular index of 18.7. o. (P< 0.0001) at latest follow-up with no loss of correction. We recorded three superficial wound infections (one MRSA), all resolved uneventfully. There was no foreign body reaction. The use of bioabsorbable pins eliminates the need for a second anaesthetic to remove the pins with significant cost benefit without compromising outcome

The treatment of chronic osteomyelitis involves a debridement of affected non-viable tissue and the use of antibiotics. Where surgery leaves a cavity, dead space management is practised with antibiotic impregnated cement. These depots of local antibiotics are variable in elution properties and need removal. We review the use of bioabsorbable synthetic calcium sulphate as a carrier of gentamicin and as an adjunct in treating intramedullary osteomyelitis. A retrospective review of cases treated consecutively from 2006 to 2010 in the Royal Liverpool University Hospital was undertaken. Variables recorded included aetiology, previous interventions, diagnostic criteria, radiological features, serology and microbiology. The Cierney-Mader system was used to classify. Treatment involved removal of implants (if any), intramedullary debridement and local resection (if needed), lavage and instillation of the gentamicin carrier, supplemented with systemic antibiotics. Follow-up involved a survival analysis to time to recurrence, clinical and functional assessment (AOFAS-Ankle/IOWA knee/Oxford Hip) and general health outcome (SF36). There were 31 patients (22 male, 9 female). The mean age was 47 years (20-67). Twenty-five cases were post-surgery (6 open fractures) and 6 were haematogenous in origin. The median duration of osteomyelitis was 1.6yrs. The bones affected were 42% femur, 45% tibia, 3% radius and 10% humerus. 11 cases had diffuse as well as intramedullary involvement. 9 cases underwent segment resection and bone transport. We identified Staphylococcus Aureus in 16 and Coagulase Negative Staphylococcus in 6 cases. The median follow-up was 1.7 years (0.5-5.6). The median scores attained were: AOFAS-78, DASH-32, IOWA-71, Oxford-32. There were two recurrences. Dead space management of intramedullary infections is difficult. We describe a method for delivery of local antibiotics and provide early evidence to its efficacy. The treatment success to date is 93%. Bioabsorbable carriers of antibiotics are efficacious adjuncts to surgical treatment of intramedullary osteomyelitis

Aims: Meniscus repair has become the procedure of choice for the treatment of meniscal tears whenever possible. However, problems with healing of the repaired meniscus do exist. We have assessed both clinically and with MRI the outcome of meniscal ruptures treated with bioabsorbable arrows. Methods: 74 consecutive patients with 80 longitudinal vertical meniscal tears were treated using polylactide meniscus arrows (Bionx Implants Ltd, Tampere, Finland) during a three year period. Half of the patients had an old meniscal tear (> 6 weeks). The average length of the follow-up was 25 months (range, 6–56 months). The patients who had not received secondary surgery for failed repair during the follow-up period were examined clinically and with MRI. Results: 56 out of 80 meniscal ruptures (70%) healed clinically. However, in 7 of these asymptomatic patients the MRI showed partial healing. In repairs performed in conjunction with ligament reconstruction the healing rate was higher (82%) than in the isolated tears (62%). The poorest results were seen in the very long vertical tears with luxation of the meniscus (43% healing rate). Conclusions: Bioabsorbable arrows offer a good alternative for the treatment of meniscal ruptures, but special attention should be payed on the reliability of the þxation. In long and unstable tears we suggest combined þxation techniques to be used; arrows for the þxation of the posterior horn and inside-out sutures for the corpus area

The bead EndoPearl is bioabsorbable material which placed in the ACL graft edge, and augment the stabilization in the femoral tunnel when an interference screw is used. Our aim was to recorded the operative characteristics of this technique and the clinical results after using EndoPearl in ACL reconstruction with hamstrings graft. In 36 of our patients who had ACL reconstruction with hamstrings we used EndoPearl bead. They were 23 men and 13 women mean age 27.8 years (17–46). The graft was fixed in the femur side with interference screw. All patients followed the same p.o. rehabilitation regime. We followed them up the 1st, 2nd, 3rd, 6th and 8th p.o. month. During the last follow-up we checked the anterior drawer test, Noulis-Lachman test and in some cases pivot shift test, and in parallel Lysholm score was recorded pre-operatively and in the last examination. In this last F.U. check none of them had positive Noulis-Lachman test or pivot shift test. The anterior drawer test was negative to 32 patients and in 4 we found slight laxity in comparison with the health leg. Lysholm score showed significant improvement (mean 90.2 p.o.), and nobody had “giving way”. The application of the EndoPearl in conjunction with a bioscrew in the femoral tunnel in autogenous ACL reconstruction using semitendinosus and gracilis tendon grafts provides a significantly decreased in p.o. laxity

The surgical correction of hammertoe deformity of the lesser toes is one of the most commonly performed forefoot procedures. In general, percutaneous Kirschner wires are used to provide fixation to the resected proximal interphalangeal joint. Although these wires are effective, issues such as pin tract infection as well as difficult postoperative management by patients make alternative fixation methods desirable. The biomechanical studies suggested that the bioabsorbable implant would be a suitable fixation device for the hammer toe procedure. These wire are made of a copolymer of 82% poly-L-lactic acid and 18% polyglycolic acid. The aim of our study was to assess the clinical outcome of these two implants. We compared 100 consecutive proximal interphalangeal joint fusions performed with each implant. There was no statistically significant difference in the fusion rate at six months using either implant. However, there was significant statistical difference in cost, rate of infection, implant migration, recurrence of deformity, patient’s return to driving, walking with routine foot wear and satisfaction. There was 11% rate of reactive inflammation in the absorbable wire group but no infection. The study shows the absorbable wires are safe for fusion of proximal inter phalangeal joints

Two fixation devices for rotator cuff repair were compared in a sheep model. Surgical transection of the supra-spinatus tendon insertion was repaired using metallic OBL suture anchors or Suretac II anchors. Twelve weeks postoperatively the repair site was assessed using histology, polarized light microscopy and biomechanical testing. No important differences were found between these two repair methods. The purpose of this study was to compare traditional rotator cuff fixation devices with bioabsorbable press-fit tacks. Sixteen sheep were assigned to OBL (n=8) or Suretac (n=8) treatment groups. Four sheep shoulder joints were used as unoperated controls. Treated sheep underwent general anesthesia and a lateral arthrotomy using aseptic technique to allow transection of the supraspinatus tendon insertion. The tendon-bone interface was repaired with two fixation devices according to the manufacturer’s directions. After recovery from anesthesia the sheep were maintained in small pens for twelve weeks. After sacrifice, muscle-tendon-bone blocks were prepared for mechanical testing. The specimen underwent a preload of 25N, followed by cyclic loading (10–50N x10), then loading at 480mm/min until failure. The remaining bone-tendon interface was fixed, embedded in plastic and 100μ undecalcified histological sections were cut, polished and stained. All tendons had healed to the humerus and the repair site was two to three times larger than unoperated controls. There were no significant differences between the two treatment groups with respect to maximum load, modulus, and energy per unit area. Histological analysis is ongoing. These data suggest that these two fixation methods are functionally equivalent in this model. Press-fit fixation devices do not knot tying and they can be inserted arthroscopically so they are a convenient fixation method. This study confirms that press fit anchors and metallic anchors with sutures are equivalent for repair of bone-tendon interfaces. Funding: Smith & Nephew supplied the fixation devices for this project. Thanks to Deb McWade for technical assistance

Purpose: Arthroscopic stabilization for post-traumatic anterior glenohumeral instability is designed to minimize soft tissue dissection while achieving similar or improved outcomes relative to open techniques. This study’s purpose was to determine the rate of post-operative recurrent instability and evaluate health related quality of life (HRQL) and shoulder range of motion (ROM) following arthroscopic Bankart repair using a bioabsorbable knotless implant. Method: Forty-three patients were prospectively evaluated following arthroscopic anterior stabilization to assess for recurrent instability, HRQL, and shoulder ROM. Assessments were performed pre-operatively and 3, 6 and 12–24 months postoperatively. The HRQL measures included the Western Ontario Shoulder Instability Index (WOSI), the American Shoulder and Elbow Surgeons Score (ASES), and the Constant Score. Repeated measures ANOVA was utilized to evaluate ROM and HRQL. Results: The mean WOSI score improved from 45.67±17.99 pre-operatively to 83.16±18.58 at final follow-up. The mean ASES scores improved from 80.1±13.06 pre-operatively to 92.25±15.08, while the Constant score improved from 77.52±16.11 pre-operatively to 85.18±26.76. At final follow-up, 4 of 43 patients (9.3%) had experienced recurrent instability. For these 4 subjects, the WOSI score was significantly lower at final follow-up than those who did not experience recurrent instability (61.73±5.76 versus 84.38±16.94). The ASES and Constant scores at final follow-up were not significantly different between these two groups. Conclusion: Arthroscopic anterior stabilization using a bioabsorable tack led to a recurrent instability rate similar to previous reports, and resulted in improved HRQL and shoulder ROM. The WOSI score was better able to detect problems in HRQL related to instability than either the ASES or Constant score

Introduction and Aims: Suture anchors allow consistent reattachment of tendons and ligaments to bone. Many options are available. The purpose of this study was to compare the initial strength of two rotator cuff repair techniques. The hypothesis was that rotator cuff repair strength with anchors would be inferior to transosseous sutures. Method: Eight paired shoulders with a standardised supraspinatus defect were randomised to bioabsorbable nonsuture-based anchor or transosseous suture repair. Each specimen was then subjected to a stepwise cyclic loading protocol, utilising a custom-designed loading apparatus. Repair site migration was measured using an optical measurement system, consisting of a digital camera and custom software. Mode of failure, number of cycles and load to failure were measured for 50% (5 mm) and 100% (10 mm) loss of repair. These results were correlated with bone mineral density, age and gender. Statistical analysis utilised paired t-tests and Pearson correlations. Results: The anchors failed at the anchor-tendon interface, whereas the sutures failed through the sutures. Mean values for 50 percent loss of repair were 206 ± 88 cycles and 44 ± 15 N for the sutures, and 1193 ± 252 cycles and 156 ± 20 N for the anchors (p< 0.05). The corresponding values for 100 percent loss of repair were 2458 ± 379 cycles and 294 ± 27 N for the sutures, and 2292 ± 333 cycles and 263 ± 28 N for the anchors (p> 0.05). These results may be due to the relative less deformability of the anchors. This may be relevant clinically, as in the early post-operative period, while tendon healing to bone is occurring, anchors may offer improved strength, allowing improved initial healing. Strength was unaffected by bone quality. This may be attributed to each repair failing primarily through the repair construct or at the anchor-tendon interface, and not through bone. Strengths of this study include the use of paired specimens, the stepwise cyclic loading protocol, as well as increased accuracy of our measurement system. Limitations include the use of an in vitro model, as well as a simulated, standardised rotator cuff tear. Conclusion: Repair strength with anchors was superior to sutures. Strength was unaffected by bone quality. Anchors facilitate an arthroscopic procedure, decrease operative time, and may allow a faster post-operative recovery. This study has described a new high-resolution method of measuring tendon repair failure and may be useful in future studies

Introduction: The use of a trans-physeal, trans-articular suture anchor across a joint as a means of internal stabilisation has not previously been described. This study assesses the damage caused by the procedure to the immature porcine hip. Methods: Six twelve week old pigs underwent unilateral hip surgery. Anteroposterior pelvic radiographs were taken preoperatively and six weeks post-operatively. The acetabular index and diameter of the femoral head ossific nucleus of both hips were measured and compared. Specimens were analysed macroscopically for femoral head diameter, acetabular dimensions and for evidence of gross chondrolysis. Histological analysis was performed to assess the presence of articular chondrolysis and proximal femoral physeal arrest. Results: In four out of six specimens the rate of change of the acetabular index slowed as compared to the unoperated side, though none worsened. The diameter of the femoral ossific nucleus continued to increase in size at a similar rate to the unoperated side on radiological examination. Similar findings were seen with the macroscopic analysis. Gross and histological analysis of the articular cartilage showed only local areas of chondrolysis, related to the drilling. Metaphyseal growth at the proximal femoral physis was unaffected by the procedure. Discussion: The use of a trans-articular suture-anchor across the hip appears to cause marginal retardation of acetabular development in the normal hip. The trans-physeal approach to the hip does not appear to affect proximal femoral physeal or epiphyseal growth in the short-term, and the presence of a bioabsorbable suture within the joint did not result in chondrolysis