Can CT determine the site of traumatic osteochondral defects in the paediatric knee?

Currently the ability of pre-operative CT imaging to determine the origin of traumatic osteochondral lesions (OCL) in the knee in children is yet to be established. The surgical approach to the knee will to some extent be determined by the origin of the lesion. It is important to directly determine the site of the lesion from pre-operative scanning both to facilitate surgery, to have a better cosmetic result for the patient and have a quicker rehabilitation period. In a tertiary referral centre, from May 2004 to April 2005, eight patients were diagnosed as having an OCL. The initial reporting was done by either a senior registrar or consultant paediatric radiologist. Those children that had an OCL underwent an arthroscopy or definitive open surgery. The exact site of the lesion was then determined and recorded in the operative notes. All the original pre-operative CT scans were given to a senior paediatric radiologist. The consultant on this occasion had no access to operative findings, or original CT reports. CTs reported by the paediatric radiology department are only able to correctly identify the site of origin of the OCL 50% of the time. Recent MR scanning techniques have improved the visualization of OCL. We authors therefore feel that in the future MRI should be used to assess the paediatric knee when an acute OCL is suspected.     

Why is the adolescent joint particularly susceptible to osteochondral shear fracture?

A biomechanical investigation of the dynamic shear failure of the osteochondral region of immature, adolescent, and mature bovine cartilage bone laminates was performed. The osteochondral junction was loaded in pure shear under impact conditions through the cartilage layer only. The results indicate the adolescent tissue fails at a nominal shear stress of 2.0 MPa, whereas the immature and the mature tissues fail at 3.8 MPa and 2.6 MPa, respectively. The adolescent tissue had a significant reduction in the fracture toughness of its osteochondral junction compared with that of the immature or mature tissues. The fracture toughness, describing the energy required to initiate and propagate a crack to failure, was 3.6 kN/m, 2.3 kN/m, and 10.2 kN/m for the immature, adolescent, and mature bovine tissues, respectively. This significant reduction associated with the adolescent osteochondral junction is explained in terms of the structural changes occurring within this important anchoring region during maturation. These findings question the wisdom of subjecting the adolescent joint to high levels and rates of loading.     

HemiCAP® implantation after failed previous surgery for osteochondral lesions of the talus

BackgroundThe aim of this study is to enhance data about the effectiveness of HemiCAP® implantation after failed previous surgery for osteochondral defects (OCDs).Methods12 consecutive patients were retrospectively included in this study. The American Orthopedic Foot and Ankle Society Score (AOFAS), the Visual Analogue Scale (VAS) score for pain, the sub-scales Pain and Disability of the Foot Function Index (FFI-P and FFI-D) Score, and the patients’ satisfaction were evaluated.ResultsAOFAS increased from poor to fair (p < 0.001), VAS score decreased from moderate to mild pain (p = 0.001), the final FFI-P and FFI-D were 37.50 ± 18.54 and 33.44 ± 16.24, respectively (p < 0.001). Five patients were not satisfied, three were moderately satisfied and four were highly satisfied. One implant repositioning, one ankle fusion (implant failing) and an additional surgery (double arthrodesis) were performed during the follow-up. Neither intra- nor postoperative complications were registered.ConclusionDespite the clinical improvement, pain was still present at the final follow-up. Metal resurfacing might not be considered a definitely valid alternative for treatment of OCDs after failed previous surgery.Level of evidenceLevel III, retrospective study.     

Osteochondral transplantation for the treatment of osteochondral defects at the talus with the Diamond twin system® and graft harvesting from the posterior femoral condyles

Background

The aim of this study is to analyze clinical results after osteochondral cylinder transplantation for osteochondral defects at the medial or lateral talar dome using the Diamond twin system (Karl Storz). We hypothesize that grafts harvesting from the posterior femoral condyles are associated with less donor site morbidity than reported by previous studies.

Methods

We have surgically treated 20 patients with an osteochondral defect of the talus by osteochondral transplantation with the Diamond twin system via an osteotomy of the ankle. The osteochondral cylinders were harvested from the posterior aspects of the femoral condyles of the ipsilateral knee. The defects at donor site were filled with a bone substitute of tricalcium phosphate (Synthricer, Karl Storz). The mean age was 25.4 years. After a mean time of 12.6 months, the screws at the medial malleolus were removed and an arthroscopy was performed. The functional outcome was evaluated with the visual analog scale for pain at walking, running, stair climbing, quality of life at the time of implant removal and at a mean follow-up of 25.8 months. Activity was assessed with the Tegner scale. Knee function was evaluated with the Lysholm score.

Results

In one case, the osteochondral cylinder did not heal and an osteochondral fragment was removed arthroscopically. In all other cases, the osteochondral cylinder was stable with surrounding cartilage. The average ICRS Cartilage Repair Assessment was 10.1 points (±1.3). All malleolar osteotomies healed radiologically. In 15 patients, a synovectomy and local debridement of the ankle were performed at second-look arthroscopy. Ankle pain at walking, running and stair climbing as measured by a visual analog scale (10-0) decreased significantly from preoperatively to the first follow-up (mean 12.6 months) and to the second follow-up (mean 25.8 months). The ankle-related quality of life increased significantly from preoperatively to postoperatively. There was no significant change in the Lysholm score. The activity measured with the Tegner activity scale increased significantly from preoperatively to the last follow-up, but only two out of nine patients continued pivoting sports.

Conclusions

Autologous osteochondral grafting with the Diamond twin system is a reliable treatment option for symptomatic osteochondral defects of the talus. After 1 year, the majority of patients had still some complaints. However, after screw removal and second-look arthroscopy, the pain and ankle-related quality of life further improved.

Clinical relevance

The donor site morbidity after graft harvesting from the posterior aspects of the femoral condyles is lower than previously reported.     

Prolonged storage of osteochondral allografts: does the addition of fetal bovine serum improve chondrocyte viability?

Osteochondral plugs were harvested from eight fresh human femoral condyles within 96 hours of donor death. The plugs were either stored in a serum-free media containing glucose, salts, and amino acids or 10% fetal bovine serum at 4 degrees C. After 28 days of storage, the osteochondral plugs were analyzed for chondrocyte viability and viable cell density using confocal microscopy, proteoglycan synthesis by (35)SO4 incorporation, and glycosaminoglycan content. Chondrocyte viability and cell density were significantly lower in grafts stored in serum-free media compared to fetal bovine serum, 27% versus 68% (P < .001) and 3250 cells/mm3 versus 8960 cells/mm3, respectively (P < .001). The metabolic activity determined by proteoglycan synthesis was significantly better in the specimens stored in fetal bovine serum (P < .01). No significant difference was detected between the glycosaminoglycan content in any of the specimens. These data suggest that the quality of osteochondral allografts as measured by chondrocyte viability, viable cell density, and proteoglycan synthesis is superior after storage in fetal bovine serum versus serum-free media. These results must be taken cautiously, however, as the clinical ramifications of storage in fetal bovine serum, including potential infectious disease transmission risks and immunogenic factors, have yet to be studied.     

Autologous osteochondral transplantation for the treatment of knee lesions: results and limitations at two years’ follow-up

Purpose

Focal chondral and osteochondral knee lesions are a common condition, particularly hard to treat, and often involve young active patients with high expectations in terms of symptomatic relief and return to sports. Autologous osteochondral transplantation allows the defect area to be restored with hyaline cartilage. The aim of this study is to analyse whether it represents a safe and effective treatment option for small–medium-sized knee chondral and osteochondral lesions in a young and active population.

Methods

Thirty-one patients (18 men, 13 women; mean age 32?±??ten; mean BMI 24?±?3) affected by focal knee chondral and osteochondral lesions were enrolled and treated with autologous osteochondral transplantation. They were prospectively followed-up for 24 months with the IKDC-subjective, IKDC-objective, and Tegner scores. Adverse events and failures were also reported, as well as the Bandi score to detect symptoms from the donor area.

Results

A significant increase was reported in all the clinical scores adopted. In particular, the IKDC-subjective score increased from a basal value of 40.3?±?16.2 to 62.6?±?18.0 at the 12 months’ evaluation, with a further significant increase up to 71.6?±?20.5 at the final 24 months’ follow-up (p?p?=?0.003), although it was not possible to regain the same pre-injury sports activity level of 5.0?±?2.2. Two failures were reported. The Bandi score revealed patients complaining of mild and moderate symptoms, not correlated to the lesion size. The presence of symptoms ascribable to the donor area was significantly correlated with a lower clinical outcome.

Conclusions

Autologous osteochondral transplantation proved to be, at short-term evaluation, a suitable option to treat small–medium sized chondral and osteochondral lesions. However, clinical improvement is slow and a significant percentage of patients develop symptoms attributable to the donor area, thus reducing the overall benefit of this procedure.     

Prospective study on diagnostic strategies in osteochondral lesions of the talus. Is MRI superior to helical CT?

Our aim in this prospective study was to determine the best diagnostic method for discriminating between patients with and without osteochondral lesions of the talus, with special relevance to the value of MRI compared with the new technique of multidetector helical CT. We compared the diagnostic value of history, physical examination and standard radiography, a 4 cm heel-rise view, helical CT, MRI, and diagnostic arthroscopy for simultaneous detection or exclusion of osteochondral lesions of the talus. A consecutive series of 103 patients (104 ankles) with chronic ankle pain was included in this study. Of these, 29 with 35 osteochondral lesions were identified. Twenty-seven lesions were located in the talus. Our findings showed that helical CT, MRI and diagnostic arthroscopy were significantly better than history, physical examination and standard radiography for detecting or excluding an osteochondral lesion. Also, MRI and diagnostic arthroscopy performed better than a mortise view with a 4 cm heel-rise. We did not find a statistically significant difference between helical CT and MRI. Diagnostic arthroscopy did not perform better than helical CT and MRI for detecting or excluding an osteochondral lesion.     

Did the neurosurgeon warn the patient of the risks?

The patient had a neurosurgical operation and came out suffering neurological damage. Was the neurosurgeon negligent in carrying out the operation? Did he negligently fail to warn the patient of the risks? If the neurosurgeon was negligent, on what basis are the damages to be assessed? These issues arose in Chester v Afshar (2002) EWCA Civ 724; (2002) 3 All England Law Reports 552.     

Does the thickness of the vertebral subchondral bone reflect the composition of the intervertebral disc?

Degeneration of the intervertebral disc, seen radiologically as loss of disc height, is often associated with apparent remodelling in the adjacent vertebral body. In contrast, maintenance or apparent increase in disc height is a common finding in osteoporosis, suggesting the properties of the intervertebral disc may be dependent on those of the vertebral body or vice versa. We have investigated this relationship by measuring the radiological thickness of the subchondral bone and comparing it to the chemical composition of the adjacent disc. Sagittal slabs were sampled from lumbar spines obtained at autopsy and X-rayed microfocally. The thickness of the subchondral bone was measured and correlated with the composition of the adjacent intervertebral disc. Eighty-three cadaveric endplates were studied from individuals aged 17–85 years. There was regional variation in thickness of the subchondral bone, being greater adjacent to the annulus than the nucleus, and the endplates cranial to the disc were thicker than those caudal. There was a positive correlation between the thickness of the subchondral bone and the proteoglycan content of the adjacent disc, particularly in the region of the nucleus. A weaker correlation was seen here between water content and thickness, whilst there was no significant correlation at the annulus or between the bone thickness and collagen content. The positive relationship between the radiographic thickness of vertebral subchondral bone and the proteoglycan content of the adjacent disc seen in human cadaveric material could be due to the bone responding to a greater hydrostatic pressure being exerted by discs with higher proteoglycan content than by those with less proteoglycan present. It is suggested that while this is true in normal specimens, the relationship becomes altered in disease states, possibly because of changes to the nutritional pathway of the disc, with resultant endplate-bone remodelling affecting the flow of solutes to and from the intervertebral disc.     

Cervical arthroplasty: the beginning, the middle, the end?

Cervical arthroplasty has developed as an alternative to spinal fusion for the treatment of cervical radiculopathy and myelopathy. The popularity of artificial discs has grown as the evidence of complications following arthrodesis has increased, making the theoretical advantages (motion preservation, altering the natural history of disease, prevention of adjacent segment disease) of disc replacement more attractive. However, as more discs are implanted and the length of follow-up increases, reported complications such as heterotopic ossification, device migration and spontaneous fusion of arthroplasty devices are growing. As a result, surgeons and patients face a challenge when deciding between motion-preserving or fusion surgery. Currently, there is inadequate evidence to promote extensive use of artificial discs for cervical spondylosis, despite promising short-term and intermediate clinical outcomes. However, there is also insufficient evidence to cease using them completely. The use of arthroplasty over fusion in the long term can only be justified if the incidence of adjacent segment disease decreases as a result. Despite the level of investment and research into arthroplasty outcomes, long-term follow-up has yet to be completed and has not convincingly demonstrated the effect of artificial discs on adjacent segment disease. Further long-term randomised trials are necessary to determine whether cervical arthroplasty is able to reduce the incidence of adjacent segment disease and, in doing so, replace arthrodesis as the gold standard treatment for cervical spondylosis.     

Compliance: the patient, the doctor, and the medication?

Noncompliance can be defined as covert nonadherence to prescribed medication used for the prophylaxis of allograft rejection and threatening impaired kidney histology or function. It is an increasingly significant long-term problem in transplantation as the failure rates from other causes have diminished. Formal approaches to diagnosis, prophylaxis, and treatment, together with a greater understanding of what should be regarded as a syndrome, are thus increasingly important components of reducing the chronic attrition of graft function and survival. It is possible to classify noncompliant behavior using four facets of the syndrome: timing, frequency, origin, and diagnostic certainty. There are a number of different ways of approaching diagnosis, such as observation of behavior through pill counting or electronic measurements of pill container opening; blood level measurement of relevant drugs; physical examination; and observation of the consequences. However, the only certainty of diagnosis comes from direct patient admission of nonadherence to the prescribed immunosuppression. It is possible to define the highest risk patients through assessment of a number of patient-, drug-, and physician-associated variables, and then to influence the outcome through education, compliance monitoring, and simplified regimens targeted to the highest risk patients. It is important for all transplant units to address the issues raised by noncompliance if the chronic loss of allografts is to be reduced.     

Rectal cancer. Is the surgeon the variable in the outcome?

Four factors influence the outcome of rectal surgery: tumour biology, stage of lesion, type of surgery performed and the performing surgeon himself. Tumour biology and tumour stage depend on each other and are not influenced on by the surgeon, while he seems to have a great influence on the latter two factors. This influence mainly consists of the following: training, volume, individual skill and experience.     

Does the fabella contribute to the reinforcement of the posterolateral corner of the knee by inducing the development of associated ligaments?

The fabellofibular (FF) and arcuate ligaments are closely colocated at the posterolateral corner of the knee. However, a bony fabella is often absent in Japanese subjects. We investigated these structures morphometrically using 212 knees. A thick FF ligament was found in 38.1% (40/105) of knees with a hard fabella. When identified histologically, a bony fabella accompanied a thick FF in 82.8% (24/29). Conversely, a thin or indefinite FF ligament and an elastic-textured fabella co-existed in 77.9% (60/70) of knees. There were no strong correlations between the morphology of the fabella and the arcuate ligament. Thus, a hard or bony fabella seemed to relate to thickening of the FF ligament. In contrast, the thicknesses of the FF and arcuate ligaments were negatively correlated. When the FF ligament was more than 5mm thick, indicating that it was as strong as the lateral collateral ligament, no arcuate ligament could be identified. Conversely, a thin or indefinite FF ligament often accompanied a well-developed arcuate ligament (61.9%, 96/155). Our observations suggest that these ligaments act in a complementary manner to stabilize the posterolateral corner. A possible common function is fixation of the popliteal tendon on the joint capsule and lateral meniscus, rather than direct stabilization against rotation stress.