[Treatment of cartilaginous defects in the knee: recommendations from the Dutch Orthopaedic Association]. / Behandeling van kraakbeendefecten in de knie: advies van de Nederlandse Orthopaedische Vereniging.

Cartilaginous defects in the knee occur frequently and can cause the patient considerable limitations. They are diagnosed and classified by means of MRI and arthroscopy. The surgical options available to treat deep chondral lesions include bone marrow stimulation techniques (microfracture treatment), chondrocyte therapies (autologous chondrocyte implantation) and tissue replacement therapies (osteochondral autologous transplantation). Microfracture treatment and osteochondral autologous transplantation are suitable for treating chondral lesions that extend to the subchondral bone and are smaller than 2 and 4 cm2, respectively. Autologous chondrocyte implantation is a suitable method for treating single symptomatic chondral lesions larger than 2 cm2 in adults up to 50 years of age. There are no significant differences regarding the effectiveness of microfracture treatment, autologous chondrocyte implantation and osteochondral autologous transplantation for small defects: all show good clinical and functional short- and medium-term results. New second- and third-generation autologous chondrocyte implantation techniques seem to yield more sustainable tissue repair and better clinical long-term results for lesions larger than 4 cm2 in comparison to microfracture treatment.

SUSHI: the Super Simple Hip score for younger patients.

We describe the development of a simple patient-based score for young patients with hip problems which concentrates on activities that are difficult for someone with a hip problem and includes an activity rating scale that measures the highest level of physical activity reached during the past year. We compared the super simple hip score (SUSHI) with the more extensive hip osteoarthritis outcome score (HOOS) and evaluated the validity, sensitivity to change and floor and ceiling effects of the SUSHI score. We found that the SUSHI score is an adequate score to measure hip problems and that this score was preferred to the HOOS score by patients.

Orthopaedic management of Hurler's disease after hematopoietic stem cell transplantation: a systematic review.

OBJECTIVE: The introduction of hematopoietic stem cell transplantation (HSCT) has significantly improved the life-span of Hurler patients (mucopolysaccharidosis type I-H, MPS I-H). Yet, the musculoskeletal manifestations seem largely unresponsive to HSCT. In order to facilitate evidence based management, the aim of the current study was to give a systematic overview of the orthopaedic complications and motor functioning of Hurler's patients after HSCT. METHODS: A systematic review was conducted of the medical literature published from January 1981 to June 2010. Two reviewers independently assessed all eligible citations, as identified from the Pubmed and Embase databases. A pre-developed data extraction form was used to systematically collect information on the prevalence of radiological and clinical signs, and on the orthopaedic treatments and outcomes. RESULTS: A total of 32 studies, including 399 patient reports were identified. The most frequent musculoskeletal abnormalities were odontoid hypoplasia (72%), thoracolumbar kyphosis (81%), genu valgum (70%), hip dysplasia (90%) and carpal tunnel syndrome (63%), which were often treated surgically during the first decade of life. The overall complication rate of surgical interventions was 13.5%. Motor functioning was further hampered due to reduced joint mobility, hand dexterity, motor development and longitudinal growth. CONCLUSION: Stem cell transplantation does not halt the progression of a large range of disabling musculoskeletal abnormalities in Hurler's disease. Although prospective data on the quantification, progression and treatment of these deformities were very limited, early surgical intervention is often advocated. Prospective data collection will be mandatory to achieve better evidence on the effect of treatment strategies.

Postural instability in Charcot-Marie-Tooth type 1A patients is strongly associated with reduced somatosensation.

In order to determine the influence of somatosensory impairments, due to the loss of large myelinated fibres, on the postural stability of Charcot-Marie-Tooth 1A (CMT) patients, a cross-sectional balance assessment was done. Nine CMT patients were compared with eight patients with a distal type of Spinal Muscular Atrophy (SMA), and 11 healthy control subjects. The balance assessment consisted of four tasks: quiet barefoot standing on a stable versus compliant surface, with eyes opened or closed. Force plate signals were used to calculate the velocity of the centre of pressure of the ground reaction forces. The patients' distal muscle force (MRC scale), vibration detection threshold (Rydel-Seiffer tuning fork) and superficial tactile sensation (Semmes-Weinstein monofilaments) were clinically assessed. Compared to the healthy subjects, postural stability of both patient groups was seriously impaired, however, increased visual dependency was only found in the CMT patients. The postural instability of the CMT patients correlated significantly with decreased vibration sense only. The strength of the correlation increased with task complexity. It is concluded that somatosensory deficits substantially contribute to impaired postural stability and increased visual dependency in CMT patients.

Fast responses to stepping on an unexpected surface height depend on intact large-diameter nerve fibers: a study on Charcot-Marie-Tooth type 1A disease.

The contribution of reflexes from the large myelinated afferents in the control of normal and perturbed gait in humans is a highly debated issue. One way to investigate this topic is by studying normal and perturbed gait in patients lacking large myelinated fibers in the distal limb (Charcot-Marie-Tooth [CMT] type 1A disease). Such patients should have delayed and decreased reflexes if the latter depend on these large myelinated fibers. To elicit the reflexes, both patients and controls had to step on a platform that was either at the same level or lowered by 5 cm. In control subjects, landing on a level surface induced short-latency responses in the biceps femoris and tibialis anterior muscles, whereas such responses were largely absent in the patients. Similarly, stepping down unexpectedly induced a very fast muscle synergy, leading to a brake of the forward propulsion in the controls, which was significantly reduced and delayed (on average 32 ms) in the patients. The observed changes correlated with both sensory and motor deficits. Nevertheless, it is concluded that the results are primarily related to the sensory deficits, since the delayed or absent responses appeared in both upper and lower leg muscles, whereas only the latter showed motor deficits. The data are taken as evidence that large-diameter afferents from the distal leg are essential for fast reflex activations induced by stepping on a level or lowered surface unexpectedly.

Hitting a support surface at unexpected height during walking induces loading transients.

The impact phase during walking is sometimes characterised by an early loading peak, termed 'transient', followed by a brief decline in the force profile, termed 'unloading phase'. It was hypothesized that transients occur more frequently when subjects are unaware of the landing condition, and that the unloading phase represents a yield of the leg. This was tested experimentally by introducing an unexpectedly lowered or level support surface height during walking. Furthermore, associations between the unloading phase and type of foot placement, load-rate, kinesiology and centre of pressure were investigated. The transient occurred more frequently when subjects were unaware of the surface height. The amplitude of unloading was higher in flatfooted (combined), as compared to heel and toe landings. The percentage of combined landings, as well as the amplitude and duration of unloading were highest in the first unexpected level trials (UL1) and gradually decreased in the subsequent level trials, when subjects adapted to the situation. Following the UL1 unloading phase, the foot roll-off was halted, the ipsilateral knee flexed, the onset of the contralateral swing phase was delayed, and the double support phase increased. The unloading amplitude correlated significantly with the load-rate and knee flexion. It is concluded that an unexpected surface height frequently induces an early stance transient that is followed by an unloading phase, flexion response and halt in foot roll-off. These characteristics deserve further study in the context of the frequent falls induced by uneven surfaces during walking.

Muscle reflexes and synergies triggered by an unexpected support surface height during walking.

An important phase in the step cycle is foot contact. When the moment of foot contact differs from the one expected, a fast response is needed. Such a mismatch can be caused by hitting a support surface earlier or later than expected. To study this, experiments were performed with healthy young adults who walked on a platform that was unexpectedly at a lowered (5 cm) or at a level height. Glasses blocked the lower visual field. In the unexpectedly lowered trials, the absence of expected heel contact triggered responses in the ipsilateral anti-gravity muscles [ipsilateral medial gastrocnemius (MGi), ipsilateral rectus femoris (RFi)] and contralateral flexor muscles [contralateral tibialis anterior (TAc), contralaterial biceps femoris (BFc)] with latencies of 47-69 ms. After the delayed heel contact, enhanced activity was found in the MGi, RFi, and TAc muscles. This specific muscle synergy was presumably activated to arrest the forward propulsion of the body. In contrast, when the surface was unexpectedly at level height, the subjects expected to step down, and the leg briefly yielded. A muscle synergy was activated at 46-81 ms that flexed the ipsilateral knee (TAi, BFi, RFi) and extended the contralateral one (MGc, BFc) to unload the perturbed leg and delay the contralateral swing phase. Both conditions triggered a fast functionally relevant muscle synergy because of a mismatch between the expected and actual sensory feedback at the moment of foot contact. The results are consistent with an internal model that compares the expected with the actual sensory feedback. The short latency of the response suggests a subcortical, possibly cerebellar pathway.

Ambulatory disabilities and the use of walking aids in patients with hereditary motor and sensory neuropathy type I (HMSN I).

PURPOSE: To determine the level of ambulatory disability and the use of walking aids in well-ambulant Hereditary Motor and Sensory Neuropathy type I (HMSN I) patients, and to identify the related demographic, physical and psychological variables. METHODS: Seventy-five well-ambulant HMSN I patients, aged 20-58 years, were measured in a cross-sectional assessment, addressing disability of ambulation and mobility (Sickness Impact Profile), demographics, muscle strength (Medical Research Council), use of walking aids, physical activity (actometer), fatigue (Checklist Individual Strength), and quality of life (EuroQoL). RESULTS: Seventy-two percent of the patients perceived a significant amount of ambulatory disability. These patients were less active, and more fatigued compared to patients without ambulatory disability, and healthy reference groups. The total patient sample showed marked distal paresis (mean MRC = 3.3), a high level of pain-discomfort (76%), but normal levels of employment (62.7%) and anxiety-depression (20%). Walking aids were used by 49% of the patients. These patients were older, less active, more fatigued, had less muscle strength, and perceived more disabilities of ambulation and mobility than non-users. Of the patients without walking aids, 41% perceived a significant amount of ambulatory disabilities. CONCLUSION: Ambulatory disability frequently occurred in well-ambulant HMSN I patients. The use of walking aids was not completely in accordance with the perceived ambulatory disability. Therefore prescription requires specific attention as well as complaints about pain and fatigue.