Maturation of Gait Following Rotationplasty - A Three-Dimensional Analysis of 6 cases

Richard D. Beauchamp, M.D., FRCSC


Gait, the process of moving one's body through space, can be assessed in many ways. Basic measurement techniques include, clinical examination, radiographic scanning, video observation, temporal spatial measurements and direct measurement methods.

Clinical examination involves physical measurements of joint range of movements, leg length discrepancies, muscle tone, balance, joint contractures, muscle strength and torsional deformities.

X-rays can be used to diagnose a condition as well as to assess the pre or postoperative anatomy.

Observational analysis of a person's gait can be use to first give an overall impression looking at symmetry, cadence, and trunk alignment. The advantage of the observational gait analysis is that the technique is available to any one. It is routinely used on a daily basis but the actual observation of a person does require a systematic approach. Koman has developed a rating scale that will train the observed to approach and analyze gait with a very analytical method. The disadvantage to relying strictly on observation when assessing one's gait is that often the observer can see only one joint at a time and not appreciate the impact that joint or limb segmant has on the other joints. Observational analysis often is conducted on the frontal view only with little time spent viewing from the sagittal plane and, apart from viewing the line of progression; virtually no transverse plane assessment is done. Although we all claim to have "wonderful" memories, storage and retrevial of an observational gait analysis is inaccurate and non reproducible.

Basic measurement techniques rely on the use of video recording. The advantages of this system are the ability to view in slow motion and freeze the frame for detailed inspection. Sagittal and frontal planes can be assessed. Retrieval of the data can be managed with appropriate storage capabilities. Still, the untrained observer will have difficulty integrating all the joints and limbs into their respective roles contributing to the overall gait assessment. Temporal spatial measurements can calculate velocity, cadence, step and stride lengths. These figures however only measure outcomes.

Direct patient measurements can include electrogoniometers to assess actual joint range of movements during gait. Several joints can be measured at once. Plantar pressure measurements (F Scan) show the forces transmitted/ generated by the foot striking the sensors. Electromyography tells us the muscle firing activity in various phases of both the swing and stance phase of the gait cycle. Optical tracking refers to the generation of values integrating the kinematics and the kinetics of ambulation. These systems can be active, where LED markers are tracked, or passive where reflective markers are placed on various landmarks or through virtual marker formation and subsequent output analyzed.

Gait Analysis System

We are fortunate to have the ability to analyze our patients following surgical procedures that may result in terminal amputations or intercalary amputations as seen following rotationplasties. The Shriners Gait Lab at Sunny Hill health Centre for Children in Vancouver, B.C., has been in operation for 7 years. We have been able to conduct a thorough assessment of these patients with a physical examination, video assessment, kinematic and kinetic analysis as well as electromyography and plantar pressure profiles. Oxygen consumption oar cost can be used to measure walking efficiency. The "team" consists of a kinesiologist, a physiotherapist and an orthopedic surgeon.

The Study

6 patients were assessed following surgical treatment of their tumors. 4 patients underwent rotationplasty for distal femoral osteogenic sarcoma. 1 patient underwent a rotationplasty for osteogenic sarcoma of the proximal tibia and one patient had an above knee amputation (trans femoral) for aggressive fibromatosis.

Improved survival rates for neoplasms in children and young adults today can be attributed to improved treatment methods including radiation and chemotherapy. Surgical intervention in conjunction with other treatments also can result in significant prolongation of life. With this improved survival rate, we now must ensure optimum long-term function not just survival.

Malignant tumors of the thigh and femur in the past may have required a hip disarticulation or even a hindquarter amputation. These procedures, although may be life saving, are extremely disabling for the patient. They experience significant increased oxygen costs to walk. Prosthetic fitting is difficult. There is also a serious impact exerted on other adjacent joins such as the sacro-iliac and the spine. Patient acceptance is often poor.

A trans-femoral amputation also demonstrates increased oxygen costs but not as high as that of a hip disarticulation. Prosthetic knee design and patient acceptance may be issues for some to consider. Altered gait mechanics following an above-knee amputation can be significant. Most patients undergoing trans femoral amputations have some degree of phantom limb pain lasting for months to years in duration.

When assessing the function of patients who have undergone an above knee amputation, hip disarticulation or knee arthrodesis, the metabolic costs of amputee ambulation are significantly greater than normal (1). Patients with resection and prosthetic knee replacement have lower energy costs than an above-knee amputee. (2) Generally, the longer the residual limb, the better the function. (3).

Even a below-knee amputation has its drawbacks. Knee joint proprioception is altered. (4) In comparing function following rotationplasty, patients with rotationplasty walked more efficiently than wither knee fusions or above-knee amputees. They walked at a faster velocity and consumed less oxygen. (5)

Rotationplasty is a surgical procedure that has been modified from the historic "Van-Ness procedure" described in 1950 by Dr. C. P. Van Ness ago to treat proximal focal femoral deficiency (PFFD). The Van-Ness procedure differs from rotationplasty in that the PFFD patients have abnormal and very unstable hip joints. The osteotomy was performed through the metahpyseal / diaphyseal area of the tibia and was often associated with some recurrence of the deformity requiring a repeat procedure. A Rotationplasty involves the resection of pathological bone usually adjacent to the knee joint. Dr. J. Borggreve initially described it in 1930 for treatment of a severe infection involving the distal femur in an adult. Whether the distal femur or the proximal tibia is resected, it is a form of intercalary amputation with preservation of the foot and ankle, which, ideally, are then situated at the level of the contralateral knee joint. The residual limb is rotated 180 degrees and the residual femur and tibia are joined together with a plate and screws, an intramedullary rod or an external skeletal fixation system. At times a vascular resection and subsequent vascular repair are required involving the vein or artery or both. Nerve resections generally are not performed and if necessary usually eliminate a rotationplasty as the procedure of choice for that patient. Usually the muscles are attached to a different origin – the gastrocnemius to the sartorius or rectus femoris and the tibialis anterior to the medial hamstrings

The patients are often kept non-and partial weight bearing with the prosthetic knee "locked" until there is evidence of healing of the femur and tibia. Early fitting with a custom prosthesis is done with the patient's rotated ankle joint effectively functioning as a knee joint with ankle plantar flexion substituting for knee extension and the ankle dorsiflexion substituting for knee flexion. This means the gastrocnemius muscle should assume the role of the quadriceps muscle to extend the prosthetic leg and the tibialis anterior muscle assuming the role of the hamstrings to flex the prosthetic leg.

The result is the creation of a functional below-knee amputation whereas the option prior to the rotationplasty procedure would have been at least a trans-femoral amputation or higher. The resultant rotationplasty patient therefore has a residual limb that is more efficient than a terminal amputation, is more physiological and usually avoids the development of phantom limb pain. All of these benefits also led to overall improved psychological effects.

In summary, a rotationplasty is a form of intercalary amputation and reimplantation which preserves the nerve supply to the foot and therefore preserves power and movement while offering the patient the prospect of a medical and surgical cure from their malignant tumor. Complications from the rotationplasty are probably similar to those occurring following above knee amputations. The survival rates are no lower with a rotationplasty than with the historic terminal amputation however, we feel the lifestyle is superior with a rotationplasty.

Gait Maturation

Gait maturation following rotationplasty begins very early following surgery. The physiotherapist while in hospital initiates ankle joint movement, both active and passive. Rehabilitation also involves strengthening the local anatomy of the leg and assisting with general strengthening of the patients as frequently they are receiving chemotherapy and often are quite debilitated from that.

Results:

Figure 1

Figure 2

 

Gait analyses were conducted from 6 months to 4 years post surgery.

Kinematics

Improved swing phase control of hip flexion was seen over time.

Increased peak knee flexion occurred.

Hip joint angles showed better overall range of movement with improved hip extension in terminal stance by 2 years following rotationplasty.

Kinetics:

Improved push off and propulsion both on the vertical and frontal forces was seen.

Electromyography:

The firing of the tibialis anterior muscle on the rotationplasty side occurred at the same time phase as the hamstrings. Similarly the gastrocnemius fired at the same phase, as did the quadriceps.

Maturation of gait in children begins with the development of gait attributes as described initially by Inman (6). Children initially walk with stiff knees and a wide base of support. They have poor balance and equilibrium. Learning to walk for children is an instinctive rather than cognitive feature, which depends on the progressive maturation of the central nervous system. Following rotationplasty, maturation of gait becomes a cognitive event rather than instinctive and does require intervention and rehabilitation. Unlike children first learning to walk, reambulation following rotationplasty does not depend on progressive maturation of the CNS but rather, must be relearned requiring the expertise of physiotherapists and prosthetists.

Conclusion

Figure 3

Figure 4

 

  • We have identified gait changes post rotationplasty on both the ipsilateral and also on the contralateral sides.
  • We have recognized abnormalities in gait that require treatment. Muscle weakness and joint stiffness are two such conditions. Return of proprioception is a unique concern in these patients.
  • The muscles have been altered and must assume a new role. Can these muscles be retrained?
  • Temporal and spatial characteristics show improved step and stride length.
  • Kinematics revealed increased range of movement after several years.
  • Kinetics showed propulsion was better with a rotationplasty than with an above-knee amputation. Propulsion post rotationplasty also improved over the 2 years studied.
  • Electromyography showed the altered muscles have "learned" their new roles – is this acquired through rehabilitation or is it inherent to normal gait?

References:

 

    1. Czerniecki, J.M., Arch. Of Physic. Med. & Rehabil. 77:53-8, 1996

 

    1. Otis et al. JBJS 67A: 606-11, 1985

 

    1. Waters et al. JBJS 58A: 42-6, 1976

 

    1. Liao, K.J. et al. Am. J. of Knee Surgery. 8(3): 105-9, 1995

 

    1. McClenaghan et al. JBJS 71A: 117882, 1989

 

    1. Inman, V.T., Ralston, H.J., Todd, F. Human Walking. Baltimore: Williams & Wilkins, 1981.

 

 

Authors address:

 

Dr. Richard Beauchamp, M.D.
British Columbia Children's Hospital
4500 Oak Street
Vancouver, BC
Canada