Acute patellar dislocation: how skeletal maturity affects patterns of injury

OBJECTIVE

The main objective of this study was to understand the role of skeletal maturity in the different patterns of osteochondral and ligamentous injuries after an acute lateral patellar dislocation.

MATERIALS AND METHODS

Two radiologists independently reviewed MRIs of 212 knees performed after an acute lateral patellar dislocation to evaluate the presence of high-grade patellar osteochondral injury, femoral osteochondral injury, and medial patellofemoral ligament injury. The association of skeletal maturity (indicated by a closed distal femoral physis), age, sex, and first-time versus recurrent dislocation with each of these various lesions was analyzed using Chi-square or T test, and multivariable logistic regression with estimation of odds ratios (OR).

RESULTS

Skeletal maturity was significantly associated with high-grade patellar osteochondral injury [OR=2.72 (95% CI 1.00, 7.36); p=0.049] and femoral-side MPFL tear [OR=2.34 (95% CI 1.05, 5.25); p=0.039]. Skeletal immaturity was significantly associated with patellar-side MPFL tear [OR=0.35 (95% CI 0.14, 0.90); p=0.029].

CONCLUSION

Patterns of injury to the patella and medial patellofemoral ligament vary notably between the skeletally immature and mature, and these variations may be explained by the inherent weakness of the patellar secondary physis.

Dual-tissue transplantation versus osteochondral autograft transplantation in the treatment of osteochondral defects: a porcine model study

BACKGROUND

Osteochondral injury is a common sports injury, and hyaline cartilage does not regenerate spontaneously when injured. However, there is currently no gold standard for treating osteochondral defects. Osteochondral autograft transplantation (OAT) is widely used in clinical practice and is best used to treat small osteochondral lesions in the knee that are < 2 cm² in size. Autologous dual-tissue transplantation (ADTT) is a promising method with wider indications for osteochondral injuries; however, ADTT has not been evaluated in many studies. This study aimed to compare the radiographic and histological results of ADTT and OAT for treating osteochondral defects in a porcine model.

METHODS

Osteochondral defects were made in the bilateral medial condyles of the knees of 12 Dian-nan small-ear pigs. The 24 knees were divided into the ADTT group (n = 8), OAT group (n = 8), and empty control group (n = 8). At 2 and 4 months postoperatively, the knees underwent gross evaluation based on the International Cartilage Repair Society (ICRS) score, radiographic assessment based on CT findings and the magnetic resonance observation of cartilage repair tissue (MOCART) score, and histological evaluation based on the O'Driscoll histological score of the repair tissue.

RESULTS

At 2 months postoperatively, the ICRS score, CT evaluation, MOCART score, and O'Driscoll histological score were significantly better in the OAT group than the ADTT group (all P < 0.05). At 4 months postoperatively, the ICRS score, CT evaluation, MOCART score, and O'Driscoll histological score tended to be better in the OAT group than the ADTT group, but these differences did not reach statistical significance (all P > 0.05).

CONCLUSIONS

In a porcine model, ADTT and OAT are both effective treatments for osteochondral defects in weight bearing areas. ADTT may be useful as an alternative procedure to OAT for treating osteochondral defects.

Incidence and concomitant chondral injuries in a consecutive cohort of primary traumatic patellar dislocations examined with sub-acute MRI

PURPOSE

To present age- and sex-specific cumulative annual incidences of primary traumatic lateral patellar dislocation (LPD) and to detail patient characteristics and concomitant chondral injuries including osteochondral fractures, as visualized on magnetic resonance imaging (MRI), in a large consecutive cohort of knee-injured individuals.

METHODS

Data on primary traumatic lateral patellar dislocations were collected from a large consecutive cohort of knee injuries examined with sub-acute MRI in a single centre with a well-defined catchment area. Annual incidences for different age-groups in relation to gender were calculated together with the risk of concomitant chondral and osteochondral injury, during sports and in general.

RESULTS

A total of 184 primary patellar dislocations were identified in the cohort of 1145 acute knee injuries (n=175) and surgical records (n=9). Knee MRI was performed within a median of six days of injury. Median age of patients with primary LPD was 16 years (interquartile range, 14-21; range, 9-47) and 41% were females. Males were significantly older than females at the time of injury (median age 17 vs. 15, P = 0.021) and sustained their primary LPD during sports more often than females (65 vs. 40%, P < 0.001). Primary LPD occurred most frequently at the age of 13 to 15 years where the annual incidence was 125 (95% CI, 96-160) per 100,000 persons. The overall annual incidence of primary LPD was 14 (95% CI, 12-16) per 100,000 persons, with a predominance of males versus females (17 vs. 11, P = 0.01). Concomitant lesions to joint surfaces were displayed on MRI or during surgery in 75 (43%) knees. Osteochondral fractures were seen in 32 knees (18%). We found no statistically significant difference in the risk of osteochondral fracture between those injured during sports or during leisure activity (14 vs. 24%, P = 0.08).

CONCLUSIONS

The annual incidence of first-time patellar dislocation was found to be 14 per 100,000 individuals with the highest incidence found among those aged 13-15 years. Primary LPD was more common among males and was sustained during sports activity in 55% of the cases. Associated injuries to the chondral surfaces should be expected in 43% of knees with primary LPD where 18% represent osteochondral fractures.

Direct 3D printing of decellularized matrix embedded composite polycaprolactone scaffolds for cartilage regeneration

Treatment options for large osteochondral injuries (OCIs) are limited by donor tissue scarcity, morbidity, and anatomic mismatch. 3D printing technology can produce patient-specific scaffolds to address these large defects. Thermoplastics like polycaprolactone (PCL) offer necessary mechanical properties, but lack bioactivity. We fabricated 3D printed PCL scaffolds embedded with polylactic acid microspheres containing decellularized cartilage matrix (DM). DM incorporation within polylactic acid microspheres prevented its thermal degradation during the 3D printing process. The scaffolds replicated the mechanical properties of native cartilage and demonstrated controlled release of DM proteins. Human mesenchymal stem cells (hMSCs) seeded on the composite scaffolds with DM and cultured in basal media self-assembled into aggregates mimicking mesenchymal condensates during embryonic development. The DM composite scaffolds also induced higher expression of biochemical markers of cartilage development than controls, providing evidence for their translational application in the treatment of OCIs. The present study demonstrates the potential of direct incorporation of DM with thermoplastics for 3D printing of patient-specific scaffolds for osteochondral regeneration.

Good subjective outcome and low risk of revision surgery with a novel customized metal implant for focal femoral chondral lesions at a follow-up after a minimum of 5 years

BACKGROUND AND PURPOSE

Patients with focal cartilage lesions experience functional impairment. Results for biological treatments in the middle-aged patient is poor. Previous studies with focal prosthetic inlay resurfacing have shown a higher risk of conversion to total knee replacement at mid-term follow-up. A novel customized implant (Episealer, Episurf, Stockholm, Sweden) has been proposed to improve implant positioning and survival. The primary objective was to assess subjective-, objective function and implant survival at a minimum of five years after surgery.

MATERIALS AND METHODS

The inclusion criteria were patients aged 30-65 years with symptomatic focal chondral defects in the medial femoral condyle, International Cartilage Research Society grade 3 or 4 and failed conservative or surgical treatment. Minimum follow-up of 5 years. Clinical and radiologic assessments were made. Patient-reported outcome measurements at the latest follow-up were compared with the baseline data for the Knee injury and Osteoarthritis Outcome Score (KOOS), the EuroQoL (EQ-5D), the Tegner Activity Scale and a Visual Analog Scale of pain (VAS 0-10).

RESULTS

Ten patients with the mean follow-up period of 75 months (60-86 months, SD 10) were included. Signs of osteoarthritis were seen in one patient (Ahlbäck 1). No cases with revision to knee replacement. VAS for pain and KOOS showed improvements that reached significance for VAS (p ≤ 0.001) and the KOOS subscores Pain (p = 0.01), ADL (p = 0.003), Sport and Recreation (p = 0.024) and Quality of Life (p = 0.003).

CONCLUSION

A good subjective outcome, a low risk of progression to degenerative changes and the need for subsequent surgery were seen at the mid-term follow-up with this customized focal knee-resurfacing implant.

LEVEL OF EVIDENCE

Prospective case series, level 4.

Supercritical carbon dioxide dried double layer laponite XLS and alginate/polyacrylamide construct and immune response

Fabrication of immunocompatible tissue constructs for bone-cartilage defect regeneration is of prime importance. In this study, a double layer hydrogel was successfully synthesized, where alginate/polyacrylamide were formulated to represent cartilage layer (5-10 % (w/w) total polymer ratio) and laponite XLS (2-5-8% (w/w))/alginate/polyacrylamide formed bone layer. Hydrogels were dried by supercritical CO₂ at 100 and 200 bar, 45 °C, 5 g/min CO₂ flow rate for 2 h. Constructs were treated with collagen, then cellularized and embedded in cell-laden GelMA to mimic the cellular microenvironment. The optimum weight ratio of alginate/polyacrylamide:laponite XLS was 10:5 based on mechanical strength test results. The constructs yielded high porosity (91.50 m²/g) and mesoporous structure, owing to the diffusivity of CO₂ at 200 bar (0.49 × 10^-7  m²/s). Constructs were then treated with collagen to increase cell adhesion and ATDC5 cells were seeded in the cartilage layer, whereas hFOB cells to the bone layer. About 10-15 % higher cell viability was attained. The porous structure of the construct allowed infiltration of macrophages, promoted polarization and positively affected the behavior of macrophages, yielding a decrease in M1 markers, whereas an increase in M2 on day 4. The formulated tissue constructs would be of value in tissue engineering applications.

[Comparison of two methods for preparing knee osteochondral injury models in mice]

Objective

To observe the effect of using tungsten drills to prepare mouse knee osteochondral injury model by comparing with the needle modeling method, in order to provide an appropriate animal modeling method for osteochondral injury research.

Methods

A total of 75 two-month-old male C57BL/6 mice were randomly divided into 3 groups ( n=25). Mice in groups A and B were used to prepare the right knee osteochondral injury models by using needles and tungsten drills, respectively; group C was sham-operation group. The general condition of the mice was observed after operation. The samples were taken at 1 day and 1, 2, 4, and 8 weeks after modeling, and HE staining was performed. The depth, width, and cross-sectional area of the injury site at 1 day in groups A and B were measured, and the percentage of the injury depth to the thickness of the articular cartilage (depth/thickness) was calculated. Toluidine blue staining and immunohistochemical staining for collagen type Ⅱ were performed at 8 weeks, and the International Cartilage Research Society (ICRS) score was used to evaluate the osteochondral healing in groups A and B.

Results

All mice survived to the completion of the experiment. HE staining showed that group C had normal cartilage morphology. At 1 day after modeling, the injury in group A only broke through the cartilage layer and reached the subchondral bone without entering the bone marrow cavity; the injury in group B reached the bone marrow cavity. The depth, width, cross-sectional area, and depth/thickness of the injury in group A were significantly lower than those in group B ( P<0.05). At 1, 2, 4, and 8 weeks after modeling, there was no obvious tissue filling in the injured part of group A, and no toluidine blue staining and expression of collagen type Ⅱ were observed at 8 weeks; while the injured part of group B was gradually filled with tissue, the toluidine blue staining and the expression of collagen type Ⅱ were seen at 8 weeks. At 8 weeks, the ICRS score of group A was 8.2±1.3, which was lower than that of group B (13.6±0.9), showing significant difference ( t=-7.637, P=0.000).

Conclusion

The tungsten drills can break through the subchondral bone layer and enter the bone marrow cavity, and the injury can heal spontaneously. Compared with the needle modeling method, it is a better method for modeling knee osteochondral injury in mice.

Magnetic resonance imaging of elbow injuries in children

Evaluating elbow injuries is challenging because of the complex anatomy of the joint. In children, injury patterns depend on the sports-specific mechanism as well as the stage of skeletal maturity. This article reviews the anatomy of the elbow and common injury patterns seen in children, with an emphasis on MRI and the throwing athlete. Imaging pitfalls specific to children are described.

CaAlg hydrogel containing bone morphogenetic protein 4-enhanced adipose-derived stem cells combined with osteochondral mosaicplasty facilitated the repair of large osteochondral defects

PURPOSE

Cartilage repair presents a challenge to clinicians and researchers. A more effective procedure that can produce hyaline-like cartilage is needed for articular cartilage repair. Mosaic osteochondral grafts for large osteochondral defects often show poor integration between the grafts and the surrounding normal cartilage, leading to defective cracks filled with fibrous tissue instead of hyaline-like cartilage. In the present study, we aimed to repair the defective cracks with a calcium alginate (CaAlg) hydrogel containing bone morphogenetic protein 4 (BMP4)-enhanced adipose-derived stem cells (ADSCs).

METHODS

ADSCs were transduced with BMP4 (B-ADSCs). The expression of BMP4 and type II collagen was confirmed using an enzyme-linked immunosorbent assay (ELISA). Swine models of large cartilage defects of the knee were constructed and received one of the four treatments: mosaicplasty only, mosaicplasty with the CaAlg hydrogel, mosaicplasty with the CaAlg hydrogel containing ADSCs, or mosaicplasty with the CaAlg hydrogel containing B-ADSCs injected into the defective cracks. Outcomes were evaluated at 12 and 24 weeks after surgery.

RESULTS

The in vitro study showed that the osteogenic and chondrogenic activities of the B-ADSCs were enhanced compared with those of the control. In vivo, in the group that received mosaicplasty-containing B-ADSCs, osteochondral tissue was completely integrated with an intact surface. Additionally, the histological scores of the mosaicplasty-containing B-ADSCs group were significantly higher than those of the other groups. Biomechanical examination confirmed that the neocartilage possessed properties similar to those of normal cartilage.

CONCLUSIONS

Mosaicplasty and hydrogel containing B-ADSCs promoted the repair of large cartilage defects by regenerating hyaline cartilage and repairing dead spaces between osteochondral grafts and donor-site defects, thus improving the feasibility and success rate of one-stage complete repair surgery for large osteochondral defects. This proposed method provides a novel and effective means for the repair of large articular osteochondral defects.

Two Years of Follow-up Magnetic Resonance Imaging for Osteochondral Injury of the Lateral Femoral Condyle in an Adolescent Basketball Player

Chondral and osteochondral injuries of the femoral condyle are rare, and relatively few cases have been reported. Therefore, the mechanism, treatment, and findings on follow-up of these injuries are not well described. Here, we report the case of an adolescent basketball player who sustained a sports-related traumatic osteochondral injury of the lateral femoral condyle. He was treated with open reduction and internal fixation with the pull-out suture technique. Two years later, he was able to resume sporting activities at his pre-injury level with no symptoms. Magnetic resonance imaging (MRI) confirmed survival of the fixed osteochondral fragment and restoration of the congruity of the articular cartilage with no sign of delamination. This report describes the clinical outcome of this osteochondral injury of the lateral femoral condyle as seen on MRI at the 2-year follow-up and discuss the mechanism and treatment of this injury. J. Med. Invest. 66 : 213-217, February, 2019.

Comparison of pain behaviour and osteoarthritis progression between anterior cruciate ligament transection and osteochondral injury in rat models

Objectives

In this study, we compared the pain behaviour and osteoarthritis (OA) progression between anterior cruciate ligament transection (ACLT) and osteochondral injury in surgically-induced OA rat models.

Methods

OA was induced in the knee joints of male Wistar rats using transection of the ACL or induction of osteochondral injury. Changes in the percentage of high limb weight distribution (%HLWD) on the operated hind limb were used to determine the pain behaviour in these models. The development of OA was assessed and compared using a histological evaluation based on the Osteoarthritis Research Society International (OARSI) cartilage OA histopathology score.

Results

Both models showed an increase in joint pain as indicated by a significant (p < 0.05) decrease in the values of %HLWD at one week post-surgery. In the osteochondral injury model, the %HLWD returned to normal within three weeks, while in the ACLT model, a significant decrease in the %HLWD was persistent over an eight-week period. In addition, OA progression was more advanced in the ACLT model than in the osteochondral injury model. Furthermore, the ACLT model exhibited a higher mean OA score than that of the osteochondral injury model at 12 weeks.

Conclusion

The development of pain patterns in the ACLT and osteochondral injury models is different in that the OA progression was significant in the ACLT model. Although both can be used as models for a post-traumatic injury of the knee, the selection of appropriate models for OA in preclinical studies should be specified and relevant to the clinical scenario.

Cite this article: T. Tawonsawatruk, O. Sriwatananukulkit, W. Himakhun, W. Hemstapat. Comparison of pain behaviour and osteoarthritis progression between anterior cruciate ligament transection and osteochondral injury in rat models. Bone Joint Res 2018;7:244–251. DOI: 10.1302/2046-3758.73.BJR-2017-0121.R2.

No implant migration and good subjective outcome of a novel customized femoral resurfacing metal implant for focal chondral lesions

PURPOSE

Managing focal cartilage injuries in the middle-aged patient poses a challenge. Focal prosthetic inlay resurfacing has been proposed to be a bridge between biologics and conventional joint arthroplasty. Patient selection and accurate implant positioning is crucial to avoid increased contact pressure to the opposite cartilage surface. A customized femoral condyle implant for focal cartilage injuries was designed to precisely fit each patient's individual size and location of damage. The primary objective was to assess implant safety profile, surgical usability of the implant and instruments, and implant migration with radiostereometric analysis (RSA).

METHODS

Ten patients 36-56 years with focal chondral defects, ICRS 3-4 of the femoral cartilage and failed earlier conservative or surgical interventions with VAS pain > 40. The patients were followed for 2 years with subjective outcome measures (VAS, EQ5D, KOOS) and RSA. The customized implant and guide instruments were manufactured by computer-aided design/computer-aided manufacturing (CAD/CAM) techniques using MRI data.

RESULTS

VAS, EQ5D and KOOS showed improvements that reached significance for VAS (p ≤ 0.001), Tegner (p = 0.034) and the KOOS subscores ADL (p = 0.0048), sport and recreation (p = 0.034) and quality of life (p = 0.037). VAS and KOOS scores improved gradually at 3, 6 and 12 months. The improvements in EQ5D, KOOS pain and KOOS symptoms did not reach statistical significance. No infections, deep venous thrombosis or other complications occured in the postoperative period. No radiographic signs of damage to the opposing tibial cartilage was noted. The surgical usability of implants and instruments were good. RSA did not show any implant migration.

CONCLUSION

This is the first clinical report of a new customized, focal knee resurfacing system. The short-term implant safety and patient-related outcome measures showed good-to-excellent results.

LEVEL OF EVIDENCE

Prospective case series, Level 4.

Osteochondral Lesions of the Talus Treatment With Fresh Frozen Allograft

INTRODUCTION

Symptomatic talar osteochondral lesions are about 50% refractory to conservative treatment requiring a surgical solution. In the case of large chronic lesions, the use of bone graft taken from tissue bank is an alternative that enables to fill the defect without causing donor site morbidity.

MATERIAL AND METHODS

Eight patients treated with talar osteochondral allograft in lesions greater than 20mm in diameter were analyzed - 4 males and 4 females aging 39.5 years old on average. Evaluation was performed according to AOFAS scale and VAS as well as incorporation and continuation evaluations according to CT and MRI studies. A follow-up of 46.8 months on average was done.

RESULTS

A 34.6-point improvement on average according to AOFAS. A 6.7-point pain improvement on average according to VAS. Incorporation in 100% of the cases. Two cases showed partial resorption and one case showed peri-graft lysis less than 30%. There was no collapse.

CONCLUSIONS

Fresh frozen osteochondral allografts are a viable alternative when treating large osteochondral lesions, thereby avoiding morbidity of autologous donor areas or arthrodesis procedures.

Intra-articular pathology associated with isolated posterior cruciate ligament injury on MRI

OBJECTIVE

Unlike with anterior cruciate ligament injury, little is known about the prevalence of intra-articular pathology associated with isolated posterior cruciate ligament (PCL) injury in the knee. The objectives of this study were to characterize and identify the frequency of meniscal tears and osteochondral injuries in these patients, and to see if management might be affected.

MATERIALS AND METHODS

Altogether, 48 knee MRI exams with isolated PCL tears were evaluated for the presence of: grade and location of PCL tear, meniscal tear, articular chondral lesion, bone bruise, and fracture. Comparisons between PCL tear grade and location, as well as mechanism of injury when known, with the presence of various intra-articular pathologies, were made using the chi-square or Fisher's exact test as appropriate.

RESULTS

In all, 69 % of isolated PCL tears occur in the midsubstance, 27 % proximally. Meniscal tears were seen in 25 % of knees, involving all segments of both menisci, except for the anterior horn medial meniscus. Altogether, 23 % had focal cartilage lesions, usually affecting the central third medial femoral condyle and medial trochlea, while 12.5 % of knees had fractures, and 48 % demonstrated bone bruises, usually involving the central to anterior tibiofemoral joint. The presence of a fracture (p = 0.0123) and proximal location of PCL tear (p = 0.0016) were both associated with the hyperextension mechanism of injury. There were no statistically significant associations between PCL tear grade and presence of intra-articular abnormality.

CONCLUSION

Potentially treatable meniscal tears and osteochondral injuries are relatively prevalent, and demonstrable on MRI in patients with isolated acute PCL injury of the knee.

Turf Toe and Disorders of the Sesamoid Complex

A turf toe injury encompasses a wide spectrum of traumatic problems that occur to the first metatarsophalangeal joint. Most of these injuries are mild and respond well to nonoperative management. However, more severe injuries may require surgical management, including presence of diastasis or retraction of sesamoids, vertical instability, traumatic hallux valgus deformity, chondral injury, loose body, and failed conservative treatment.