Orthopaedic rehabilitation involves the care of patients who have complex musculoskeletal problems that are global in nature rather than being limited to one or two anatomic locations. It is a specialty that combines biomechanics and biology in a unique manner with an approach that focuses on improving the functional outcome for individuals with musculoskeletal disability through surgical and nonsurgical management. Orthopaedic rehabilitation comprises many traditional orthopaedic subspecialties, including amputation surgery, prosthetic and orthotic management, and the treatment of neuromuscular diseases, with a focus on the musculoskeletal system as a whole as well as on the linkages and couplings between bones, joints, muscles, and the nervous system.
This Specialty Update highlights presentations and advances in several areas of orthopaedic rehabilitation that were discussed at meetings of the Orthopaedic Rehabilitation Association, the American Academy of Orthopaedic Surgeons, and other specialty organizations over the past year.
Dynamic electromyography and motion analysis are essential tools for providing a basis for many interventions that the orthopaedic surgeon utilizes both in the operating room and in the clinic.
Joint instability can be a difficult problem for both the patient and the clinician in terms of understanding its etiology, its proposed interventions, and the outcomes of such interventions. Two recent studies examined ankle instability with use of electromyography and motion analysis1,2. It is postulated that altered afference resulting from damaged mechanoreceptors after acute lateral ankle sprain may play a role in continued functional ankle instability. This can lead to reflex inhibition of the surrounding ankle joint musculature (particularly the peroneal muscles) known as arthrogenic muscle inhibition. Palmieri-Smith et al. examined twenty-one patients with unilateral functional ankle instability and twenty-one healthy controls and assessed the ratio of the peroneal maximum Hoffmann reflex (H-reflex) to the maximum muscle wave (M-response)1. The authors found that, while healthy controls had no difference between the dominant and nondominant legs in terms of the H:M ratio and electromyographic activity, differences were found between limbs in the functional ankle instability group. The patients with functional ankle instability had significantly larger peroneal H:M ratios in the unaffected ankle as compared with the injured ankle. The authors concluded that, because arthrogenic muscle inhibition and dynamic joint stabilization are not related, rehabilitation to overcome arthrogenic muscle inhibition is not warranted as neuromuscular inhibition does not interfere with dynamic joint stabilization. Rather, rehabilitation should focus on improving peroneal muscle function to improve dynamic muscle activation.
Sefton et al. performed a case-control study in which twenty-two patients with chronic ankle instability were matched with twenty-one healthy controls to examine the role that sensorimotor function (specifically, what combination of sensorimotor variables) may play in further explaining chronic lateral ankle instability2. A significant difference was found between patients with instability and controls in terms of static balance and motor neuron pool excitability (as measured with H-reflex measurements). No differences were found between the groups in terms of dynamic balance and joint kinesthesia. The authors concluded that patients with chronic ankle instability can be seen as having more displacement (occurring at an increased velocity) in static balance traits in addition to having (to a lesser extent) blunted motor neuron pool excitability (H-reflex measurements) as compared with healthy controls. This study2 underlines the importance of utilizing a combination of static balance and motor neuron pool excitability tests when examining patients with chronic ankle instability and of developing prevention techniques and rehabilitation protocols in this patient population.
Sankar et al. utilized gait analysis to better understand recurrent clubfoot deformity3. Thirty-five patients (fifty-six feet) with an average age of 6.7 years who had recurrent deformity following the treatment of idiopathic clubfoot underwent a static analysis by a physical therapist (including range-of-motion testing and measures of lower extremity deformity) as well as computerized motion analysis and dynamic electromyography during walking trials at a self-selected speed down a 15-m walkway. After complete data collection, both clinical and kinematic data were examined. In addition, footswitch and electromyographic data were assessed, with a specific focus on tibialis anterior timing in stance phase (particularly when footswitch data indicated forefoot supination in stance). The authors concluded that recurrent clubfoot is multifactorial in terms of deformity and gait patterns. In addition to forefoot supination (almost always due to inappropriate activity of the tibialis anterior during stance), additional transverse plane deformities, including internal tibial torsion and forefoot adductus, which lead to compensatory hip external rotation during gait, are seen. Preoperative gait analysis is useful for decision-making in cases of recurrent clubfoot deformity and can change surgical planning a majority of the time (particularly with the addition of a tibial derotational osteotomy).
Shultz et al. examined the effects of obesity in children on joint kinematics and kinetics during self-selected and fast walking cadence4. Twenty volunteers between the ages of eight and twelve years participated in the study. Ten patients with a body-mass index that was greater than the ninety-fifth percentile for their age group were assigned to the overweight group, and ten patients with a body-mass index that was less than the seventy-fifth percentile were assigned to the normal weight group. The authors found that overweight children had greater absolute peak joint moments at the hip (flexor, extensor, abductor, external rotator), the knee (flexor, extensor, abductor, adductor, internal rotator), and the ankle (plantar flexor, inverter, external rotator, and internal rotator). After body weight was entered as a covariate, overweight children had greater peak ankle dorsiflexor moments. There were no kinematic differences between the two groups. The authors concluded that moments increased in all planes for all lower extremity joints, regardless of walking cadence, in overweight children. In addition, the increased ankle dorsiflexor moments in overweight children allowed for a greater braking mechanism during walking. However, the percentage increase in joint moments when a change was made from self-selected walking cadence to fast walking cadence was not significantly different for overweight and normal weight children.
The pediatric patient population is becoming increasingly active and is engaging in higher-demand activities, overburdening their developing musculoskeletal systems. As clinicians seek to return pediatric patients back to their activities in a timely fashion, rehabilitation is playing an increasingly important role.
Selective dorsal rhizotomy5 is a procedure that is utilized to decrease spasticity in patients with cerebral palsy. The long-term functional outcomes of this procedure are largely unknown. Langerak et al. examined the functional outcomes for fourteen patients with spastic diplegia who had undergone selective dorsal rhizotomy6. Outcomes before as well as one and twenty years after rhizotomy were examined. The mean age of the patients at the time of the final assessment was 28 ± 4 years, and all patients had been diagnosed with congenital spastic diplegia, had walked preoperatively, had the rhizotomy performed by the same surgeon at the same institution, and had access to intensive physical therapy before and after surgery. In terms of the body structure and function portion of the International Classification of Functioning, Disability and Health, the authors found that muscle tone, joint stiffness, and voluntary movement scores showed significant improvement after rhizotomy. In fact, at twenty years of follow-up, the median muscle tone score reduced to such a level that it was equivalent to normal muscle tone. After the initial improvements seen at one year of follow-up, none of the outcome measures from the International Classification of Functioning, Disability and Health model for body structure and function showed a further significant difference from the one-year time point to the twenty-year time point, indicating that the improvements seen at one year did not deteriorate with time. The results of this study suggest that selective dorsal rhizotomy can lead to improvements in the functional status of patients with cerebral palsy. In addition, the changes in the Gross Motor Function Classification System may be used as a tool to detect changes after intervention.
Continuing in the study of patients with cerebral palsy, Rogozinski et al. examined the efficacy of the floor-reaction ankle-foot orthosis in children7. The study was a consecutive, retrospective case series of twenty-seven patients with cerebral palsy, between the ages of seven and sixteen years, who underwent gait analysis while barefoot and while wearing a floor-reaction ankle-foot orthosis. The orthosis had been prescribed to all patients to improve a crouch gait. The authors found that mean sagittal plane dynamic range of motion of the ankle in stance was reduced significantly, from 23° ± 9° while barefoot to 10° ± 3° with the orthosis. Mean peak knee extension in midstance also improved significantly, from 29° ± 14° of flexion to 18° ± 14° of flexion. Greater degrees of preexisting knee and hip flexion contractures were correlated with decreased peak knee extension in midstance. The authors concluded that the floor-reaction ankle-foot orthosis is beneficial for patients with spastic cerebral palsy who have excessive ankle dorsiflexion with associated knee flexion during stance.
Goold and Vane examined the need for long-term monitoring of children with head injury and investigated how monitoring could be adjusted on the basis of the severity of the initial injury8. Two hundred and forty-eight patients with traumatic brain injury between the ages of thirteen and twenty-one years were examined. Demographic characteristics, Glasgow Coma Scale scores, evidence of previous neurological disorder, and the results of the OT HIMS (Occupational Therapy Head Injury Mini Screen) test (consisting of the Galveston Orientation and Amnesia Test [GOAT], the Cognistat, and a mild head injury fact sheet) were collected. Eighty-three patients displayed some form of impairment. The mean Glasgow Coma Scale score was 13.96 ± 2.16. There was no correlation between the Glasgow Coma Scale score and the GOAT or the Cognistat. The authors concluded that the lack of correlation between the Glasgow Coma Scale (representing the degree of head injury at time of admission) and the OT HIMS (representing cognitive deficit at the time of discharge) demonstrates that functional deficits (as measured with the OT HIMS) exist independently of the degree of injury. If screening for cognitive deficits is done solely on the basis of the Glasgow Coma Scale, many children will not be identified who may benefit from optimization of their functionality. Cognitive deficit screening should, therefore, be performed for all patients who are admitted with traumatic brain injury8.
Lim et al. set out to determine whether a sports injury-prevention program could modify the muscle strength, flexibility, and biomechanical properties associated with anterior cruciate ligament injury9. The biomechanical risk factors associated with noncontact anterior cruciate ligament injuries include greater knee extension and valgus moments during landing10,11, less knee flexion and more hip and knee internal rotation during single-leg landing12, and greater use of the quadriceps as a stabilizer to control the knee in females as compared with males13. Twenty-two high school female basketball players were divided into two groups (one group of eleven subjects who would participate in the anterior cruciate ligament injury-prevention program and one group of eleven controls). The group of eleven subjects who engaged in the sports injury-prevention program participated in these activities during the first twenty minutes of practice for eight weeks. The training protocol was similar to the Prevent Injury and Enhance Performance (PEP) Program as described by Mandelbaum et al.14. The authors found that, within the experimental group, improvement was seen in terms of all strength parameters, knee flexion (improved range of motion), knee flexion angles, interknee distance, hamstring-quadriceps ratio (improved hamstring strength), and maximum knee-extension torque after training. Hip flexion and ankle dorsiflexion motion did not improve after the program. The control group did not show improvement in any of these parameters. When post-training results of the experimental group were compared with the results for the control group, the experimental group had higher knee-flexion angles, greater interknee distances, lower hamstring-quadriceps ratios, and higher maximum knee abduction torques than the control group did. The authors concluded that the training program that they used can improve strength, flexibility, and biomechanical properties that may predispose the young female athlete to anterior cruciate ligament injury. The results of this study must be compared with those of other recent studies that outline neuromuscular control programs in female athletes for decreasing the risk of anterior cruciate ligament injury15.
Spinal cord injury places a substantial burden on society and is an important public health problem. In the United States, >10,000 new injuries occur each year, and approximately 250,000 individuals with spinal cord injury are living today. Saunders et al. analyzed data from the Spinal Cord Injury Surveillance system in South Carolina from 1981 to 1998 in an attempt to identify long-term trends and risk factors associated with these injuries32. The authors reported that, over the study period, there was a significant decrease in mortality of 3% each year. This decrease was likely due to, and stresses the importance of, new policies and developments in prevention (car design, seat belt use) and tertiary care. Kattail et al. also reported a significantly lower in-hospital mortality rate in a specialized spine trauma center when compared with data from the Canadian National Trauma Registry (4% compared with 7.5%)33. They emphasized the need to transfer acute spinal cord injury patients to a specialized center for care.
The United States Food and Drug Administration recently approved the first clinical trial using derivatives of human embryonic stem cells in cases of spinal cord injury. This phase-I multicenter trial consists of injecting oligodendrocytes into the spinal cord after injury, which in small-animal studies has been shown to have nerve growth-stimulating properties and to be effective for remyelinating axons. Excitement over the approval of this trial was also met with concern over potential safety issues, such as immune rejection or ectopic growth. In addition, assessing the efficacy of the therapy and the regrowth of axons may prove to be difficult. The negative impact that potential complications during this trial could have on stem-cell research and funding is a concern of many stem-cell investigators. This phase-I trial is set to be completed by early 2011.
Spinal cord injury patients have an increased susceptibility to infection, and the role of the immune system in the initial response to and recovery after spinal cord injury continues to be a major focus of preclinical and clinical research. Multiple studies have shown increased activation of destructive inflammatory cascades, with a decrease in lymphocyte function and immune function. The administration of high-dose glucocorticoid therapy in spinal cord injury patients continues to be controversial, especially in light of these immune system changes. Other preclinical studies have shown that the immunosuppressive effects of spinal cord injury were caused by ß2-adrenergic receptors; these effects could be reversed with use of ß2-adrenergic receptor blockers34. Recently, Ankeny et al. studied the role of antibody-producing B-cells in a murine model of spinal cord injury35. In this study, a larger percentage of B-cell knockout mice that had been subjected to spinal cord injury recovered locomotor function, and at a higher rate, in comparison with wild-type mice with the same injury. B-cells were present in the cerebrospinal fluid, with an accumulation of antibody and complement components at the site of injury. These antibodies were purified from the blood of control and spinal cord injury mice and were injected into naïve mice. Mice that were injected with the antibodies developed paralysis of the hindlimb on the side of injection. These results suggest that pathogenic autoantibodies could be a primary cause of secondary spinal cord injury. Translation of these results to techniques and therapies that deplete B-cells could potentially be effective for managing patients who have a spinal cord injury35.
Many patients with a spinal cord injury are wheelchair-bound. Although they can lead independent lives, they have many upper extremity problems as a result of repetitive weight-bearing and overhead activity associated with prolonged wheelchair use36,37. Shoulder pain is a common complaint of these patients, and Akbar et al. demonstrated that the risk of shoulder girdle damage is significantly higher in patients with long-term paraplegia (T2-L3) than in age-matched controls36. A group of 100 patients who had been wheelchair-dependent for at least thirty years and an age-matched group of 100 able-bodied volunteers underwent a standard clinical examination and magnetic resonance imaging. Shoulder pain was reported in 67% of the patients in the study group, compared with only 16% of those in the control group. Constant scores and Disabilities of the Arm, Shoulder and Hand scores were significantly worse in the paraplegic patients. The prevalence of a magnetic resonance imaging-confirmed rotator cuff tear was four times higher in the paraplegic group compared with the control group (63% compared with 15%; p < 0.0001). The rates of glenohumeral osteoarthritis (19% compared with 1%) and acromioclavicular arthritis (42% compared with 26%) were also significantly higher in the paraplegic group. This study shows that structural and functional changes of the shoulder joint are not age-related but rather are due to repetitive overhead reaching and the duration of wheelchair dependence36. The assistive aids and environment for these patients should be adapted to reduce damage to the shoulder joint.
In a cross-sectional study performed by Yang et al.37, the prevalence of carpal tunnel syndrome among paraplegic wheelchair users was found to be high. One hundred patients with a spinal cord injury (at T2 or below) who used a manual wheelchair for more than forty hours a week for one year were enrolled. Fifty-seven percent of the subjects had at least one symptom, most commonly numbness, consistent with carpal tunnel syndrome, with the majority (72.2%) having bilateral symptoms. Sixty percent had at least one physical examination finding consistent with carpal tunnel syndrome; diminished pinprick sensation was the most common finding. There was also a high rate of median mononeuropathy on nerve conduction studies. The results of this study stress the importance of primary prevention and patient education to preserve upper extremity function37.
Johnston et al. performed a randomized controlled trial to investigate the effects of leg cycling with and without electrical stimulation on cardiorespiratory measures in children38. A total of thirty children between the ages of five and thirteen years who had sustained a spinal cord injury at least twelve months previously were randomized to one of three groups: functional electrical stimulation leg cycling, passive leg cycling, and no cycling with electrical stimulation. Baseline cardiorespiratory measures were collected, including oxygen uptake (VO2) during an upper extremity ergometry test, the resting heart rate, forced vital capacity, and a fasting lipid profile. Exercise was performed at home for one hour three times per week for six months, and the same cardiorespiratory measures were obtained at the six-month time point. The resting heart rate, VO2 peak, forced vital capacity, and lipid values did not change over time. There was, however, a greater percentage change in VO2 peak for the functional electrical stimulation cycling group and a greater percentage decrease in cholesterol levels for the electrical stimulation group. These results suggest some improvement in respiratory status in children with a spinal cord injury who perform functional electrical stimulation cycling, but the lack of overall changes in other variables suggests that an increased intensity of exercise may be necessary to see a substantial effect38.