Lower limb amputation typically occurs as a last resort, when all measures to preserve the lower limb are exhausted. The most used transtibial amputation is the posterior flap technique.1 However, often seen after amputation is a cluster of signs and symptoms such as pain, swelling, sense of instability, bone and soft tissue atrophy, and prosthetic difficulties, resulting in decreased function. These signs and symptoms have been operationally defined by some as “inactive residual extremity syndrome.”2 An alternative to the standard amputation method is osteomyoplastic transtibial amputation, commonly called the “Ertl procedure.”2 The aim is to maximize the regenerative process after amputation through remodeling guided by surgical reconstruction and postoperative rehabilitation.
To the authors’ knowledge, there has not been a published description of a rehabilitation program after an osteomyoplastic procedure. A standard for physical therapy management after osteomyoplastic transtibial amputation needs to be described to guide future controlled study. The purpose of this article is to describe the typical clinical presentation and current physical therapy management practiced in patients with osteomyoplastic transtibial amputation, the Ertl procedure.
CONVENTIONAL SURGICAL PROCEDURE
The most common surgical approach in amputation practiced in the United States is a posterior flap approach.1 The site for amputation is determined by measurement of approximately 10–15 cm distal to the tibial plateau. The medullary canal of the tibia and fibula remains open, resulting in poor to no ability for the limb to end weight bear within the prosthetic socket. With an open medullary canal, there is an increased likelihood for venostasis (0 mm Hg venous gradient) and an increased potential for bone spur formation. With nominal to no weightbearing, regional osteopenia and adjacent degenerative joint disease can also develop.1,3
Soft tissue stabilization is created by attempting to secure the posterior myofasciocutaneous flap to the periosteum and cortex of the distal tibia. This flap often becomes detached and retracts allowing the musculature to undergo fatty atrophic degeneration, venous stasis, and poor volume for functional prosthetic fit. Further, the anterior and lateral compartments are not used in soft tissue stabilization, and these compartments also can undergo fatty degeneration in the long term. Incisions from this surgical procedure are placed over prominent bony surfaces causing a potential generator of pain. The regional circulation is disturbed secondary to venous stasis causing abnormal dilation and creation of vessels, resulting in an increased risk for arteriovenous malformation and ischemic pain.4,5
OSTEOMYOPLASTIC SURGICAL PROCEDURE
Development of the osteomyoplastic technique arose from Ertl et al.'s6 observations of the regenerative capabilities of the periosteum and was first applied to craniofacial defects of injured veterans after World War I. This technique has been subsequently applied to the patients with upper limb, transtibial, and transfemoral amputation.6
In contrast to the standard amputation surgical procedure, the osteomyoplastic technique is actual osseous (osteo-) and soft tissue (-myo-) reconstruction (-plastic), whereby the bone spurs and other osseous scarring are removed and the medullary canal is closed7 (Figure 1, personal file). There is myoplasty or reattachment of opposing muscle groups followed by a plastic closure of soft tissues. The basic aims of the osteomyoplastic procedure are to 1) stabilize the anatomical structures within the residual limb; 2) provide an end weightbearing platform for the residual limb; 3) create a cylindrical residual limb; and 4) restore normal physiology within the residual limb.6
To stabilize the anatomic structures within the distal-most residual limb, the surgeon creates a synostosis between the tibia and fibula, a “bone bridge.”7 The bone bridge is created by using osteoperiosteal flaps as the foundation for osseous regeneration. The bridge can be augmented by using a portion of the fibula and supplementing the synostosis with cancellous bone graft (Figure 2, personal file). However, screw fixation is not recommended as the screw or screws can cause stress shielding and these screws do require removal once the bridge has formed. This necessitates an additional surgery for the patient. Creation of a bony synostosis then prevents lateral deviation of the fibula, creates a stable platform for end bearing, and restores medullary venous gradient within the residual tibia.6 The myoplasty then provides the distal-most muscles within the anterior, superficial posterior, and lateral compartments attachment to one another, creating muscle-bone balance and stability within the residual limb.7 The procedure creates a long, dynamic, cylindrical limb with significant surface area, which can improve prosthetic suspension, fit, and use. The smooth contour of the limb aids in preventing localized skin breakdown because the potential for pressure points is reduced.6 The closure of the medullary canal allows return of normal venous gradient and the distal bone remains vascularized, enabling the restoration of normal physiology to the limb.4 The muscle length-tension relationship is reestablished restoring efficient use of the muscles.1 In short, the residual limb should be a well contoured, functional, and dynamic limb, accepting a prosthesis to allow the patient to ambulate and function in a relatively effortless and painless manner.
An extensive literature review and extensive clinical experience in care for those with amputation were used to formulate a standard for physical therapy after an osteomyoplastic transtibial amputation. The physical therapy intervention is presented in phases: initial presentation, examination, and plan of care.
INITIAL PRESENTATION IN REHABILITATION
From the outset, the physical therapist is an integral member of the clinical team. However, the most important team member is the patient. Besides the patient, members of the rehabilitation team are: the patient’s family, the surgeon, pain management physician, case management/social worker, prosthetist, psychologist, occupational therapist, and physical therapist. The team members should make every effort to stay in regular and consistent communication with one another, formally during Amputee Clinic, and informally, via confidential e-mail and telephone. Close communication is vital for providing quality care and minimizing risk of complications during the patient’s recovery.
Throughout the rehabilitative process, the team must be cognizant of psychosocial issues that the patient confronts, the process of coming to terms with loss. As an inpatient and typically as an outpatient, the person with amputation presents to the physical therapy clinic in a wheelchair, in pain, and reluctant to move. The person with recent amputation is in the process of coming to terms with a drastic change in body image and role within the home and work environment. The physical therapist (as with all of the team members) needs to inform the patient on what to expect during recovery and what options for functional restoration are available.
With the Ertl procedure, the intent is to render the residual limb that is useful and functional. The amputation can be a result of illness (e.g., cancer, diabetes, etc.), surgical failure, failed vasculature, or trauma. The timeframe for the patient and family to decide upon amputation may be very brief or prolonged, and many emotionally intense events can occur immediately after the surgery. The patient and the family require time to process information given to them by the clinical team members. Repeated verbal and written instruction is helpful during the initial postoperative recovery. During this time, the team needs to give encouragement and be consistent in approach.
PHYSICAL THERAPY EXAMINATION
The physical therapy examination is comprehensive and inclusive. The therapist essentially follows the Guide to Physical Therapist Practice.8 The therapist takes a detailed medical history and is apprised of the work and home environments. Because of the prevalence of comorbidities such as peripheral vascular disease and diabetes in people with amputation, it is important that the presence and level of control of the chronic conditions be considered. The patient’s desired outcomes and goals should be included, as these goals direct physical therapy care for optimal outcomes.
Reevaluation is ongoing throughout the physical therapy plan of care. The entire patient (not only the areas directly involving the residual limb) is considered. Initially, gross screening and baseline tests and measures with special testing (e.g., volumetric measurements) are conducted. The physical therapist collects data on 1) the patient’s level, location, and quality of pain and other sensation; 2) general range of joint movement and flexibility; 3) overall muscle strength and performance; 4) skin integrity and surgical incision site; 5) cardiovascular/pulmonary status; 6) static and dynamic posture and balance; 7) mobility and ability to conduct activities of self-management; 8) preprosthetic gait; and 9) transfers between bed, chair, bath, and vehicle. It must be emphasized that each examination is individualized and patient dependent.9
PLAN OF CARE—A PARTNERSHIP
It is paramount that the rehabilitation team work closely together as partners to maximize the potential of a successful outcome. And, more importantly, the patient needs to agree to, or “buy in” to, the purpose of their plan of physical therapy intervention.
The physical therapy diagnosis is individualized, depending on the presence and quality of impairments and comorbidities. The therapist strives to set reasonable, measureable, and obtainable goals with the patient. Prevention of conditions that can impede progress during the course of rehabilitation (e.g., possible development of painful bursae or neuromas, etc.) is considered when designing and executing the physical therapy plan of care.9
PREPARING THE PERSON WITH OSTEOMYOPLASTIC TRANSTIBIAL AMPUTATION FOR USE OF PROSTHESIS
Immediately after the surgery, proper maintenance of posture and body alignment is enforced. Within the first 2 weeks after surgery, isometric contraction of muscles in the unaffected limbs and proximal to the knee in the residual limb should occur. By the 4th week, active range of knee movement becomes routine and the initiation of aerobic conditioning using the upper limbs (e.g., arm bike). Vital signs are continually monitored for patient safety and modification to the physical therapy intervention.
The therapist also instructs the patient on soft tissue desensitization and residual limb care. Those subscribing to the Ertl approach rarely place compressive dressings or stocking on the residual limbs because swelling can be controlled through limb elevation and active contraction of the distal-most muscles. By 4 weeks after amputation, the patients are instructed to begin towel pulls or repetitive progressive end weightbearing and “scale exercises.” The purpose of these activities is to prepare tissues within the residual limb and to prepare the patient for enhanced perception of weightbearing on the end of the residual limb.
The therapist instructs the patient to actively contract the distal-most muscles in the residual limb, facilitating venous return. We theorize that, with active muscle contraction, the patient receives better sensory input for enhanced control of the residual limb during walking and higher level of activity. Response to postural perturbation may also be enhanced, effectively reducing risk for falls. Maintenance of residual limb volume has been consistently observed. Some patients report an increase in volume that may be attributable to an increase in residual muscle mass, actual muscle hypertrophy.
The patient needs to prepare for assuming the standing posture using two limbs once again. It is often observed that patients report back pain, and occasionally leg pain that is not directly related to amputation. The pain typically is intermittent and occurs upon prolonged sitting, rising to stand, and walking. Occasionally, a radicular pain pattern or shooting pain that travels down the limb is reported. Often these symptoms are mechanical in nature and related to poor postural and movement habits.10 Postural education and repeated movements exercise11 seem to ameliorate the majority of the mechanical pain (Figures 3 and 4). Neural mobilization of the sciatic and femoral nerves (and their respective branches) seems to significantly reduce adherent nerve root-like pain12 (Figure 5). Patients report relief and “feeling better” with manual therapy of the soft tissues and joints in the residual limb as well. Physical modalities (heat, cold, ultrasound, electric stimulation) can be applied on an “as needed” basis.
Throughout this phase of rehabilitation, the team provides emotional and psychological support to the recovering amputee. Patient education is ongoing during this phase of rehabilitation, in the effort to empower the patient to make informed decisions. All of the rehabilitation team must be mindful of the time that is required for tissues to heal after amputation. The tissues within the residual limb that underwent an osteomyoplastic procedure have new “roles.” The bone bridge is consolidating and the muscles recently attached to one another are adapting. Capillary beds and other vasculature are forming. The therapist should guide the patient to tailor the intensity and duration of exercise and activities accordingly. The therapist must be vigilant to minimize risk of complications in wound healing and overall physical condition, to prepare the patient for prosthetic use (Figure 6).
PHYSICAL THERAPY INTERVENTION: PROSTHETIC TRAINING AND REHABILITATION
After approximately 6 weeks following amputation, the patient may be able to receive a prosthesis with an initial socket for gait training. The rehabilitation team members, specifically the patient, prosthetist, and physical therapist, need to work day to day to ensure proper fit with a changing, recovering residual limb. Within the first 6 months, significant decrease in residual limb volume is expected. This may require socket changes to maintain appropriate functional fit during rehabilitation. Depending on the type of prosthetic suspension, proper sock management is vital. The therapist with the patient must monitor the wound and the patient’s skin care of the residual limb and the intact limbs.
More intensive therapeutic exercise such as trunk stabilization, strength training, and aerobic conditioning are added. The therapist and prosthetist work with the patient in their prosthetic training. Proper donning and doffing of the prosthesis is essential. Progressive gait training within the clinic, in the home, and outdoors are routine.
The patient by now is expected to be independent in 1) the home exercise program; 2) walking with assistive devices; and 3) their activities of daily living.
Preparation to return to previous function is discussed among the entire rehabilitation team. Therapeutic goals are generally modified to focus on discharge planning. The therapist modifies the intervention to meet the patient’s ideal activity level at the time of discharge. Functional activities that simulate work-related activities and sport-related activities are incorporated into the plan of care. Vital signs are continually monitored with the changing progression of treatment. The patient is expected to self-correct posture and body mechanics through many hours of practice at home through instruction by the physical therapist. Prevention of mechanical and neuropathic pain is discussed and strategies are devised by the patient and therapist. The prosthetist and the physical therapist educate the patient on good prosthetic fit to minimize risk of injury to the still-changing residual limb.
Return to work and return to sport with individualized modification are expected. The physical therapist can conduct a functional capacity evaluation, a comprehensive and standardized testing format, which delineates the patient’s readiness to return to work. This informs the team on the patient’s performance at the safest and highest level of physical demand (Figure 7).
CLINICAL OUTCOME MEASURES
Currently, there is no gold standard against which to measure clinical outcomes of patients with transtibial amputation in general,13 or osteomyoplastic amputation, specifically.14 We use a cluster of measures to encompass the patient’s perception, the functional use of the prosthesis, and the aerobic capacity of the patient: 1) the Lower Extremity Functional Scale (LEFS); 2) the Amputee Mobility Predictor (AMP); and 3) the 2-minute walk test. The purpose of the LEFS is to assess the patient’s perception of the impact of lower limb condition is on daily activities.15 The AMP is an instrument designed to measure ambulatory potential of lower limb amputees with and without the use of a prosthesis.16 The purpose of the 2-minute walk is to document change in the patient’s use of the prosthesis during walking.17
We also use the change in impairment we encounter in each patient as clinical outcomes measures. Typical impairments include 1) hip and knee joint contractures-limited passive joint range of movement; 2) control of proper static and dynamic posture and movement patterns; 3) hip and knee muscle strength and performance; 4) walking ability or level of mobility; and 5) aerobic capacity. Other measures of interest are 1) residual limb volume measurements; 2) the patient’s skill level of prosthetic and residual limb management; and 3) functional capacity to return to work and/or sport.
There are limitations to the expected outcomes set in the research literature. Much of the historic research was based on an older, dysvascular patient population. Much of the work has concerned those with standard amputation, not those with osteomyoplastic amputation and subsequent comprehensive rehabilitation. The potential of those with osteomyoplastic amputation is not fully understood. Outcome measures should be conducted on a large sample of this population to determine whether the current measures are applicable. Expectations of outcome may be elevated in those with Ertl transtibial amputation.
CLINICAL RELEVANCE AND FUTURE STUDY
Currently, we have anecdotal evidence on the advantages of implementing the osteomyoplastic approach to transtibial amputation. The physical therapy examination and plan of care are somewhat similar for those with standard amputation,18 except 1) there is little to no continuous compression of residual limb tissues after surgery; 2) we encourage active muscle contraction in the distal-most residual limb; 3) we encourage progressive end weightbearing of the residual limb; and 4) we subscribe to implementation of mechanical therapy and self-treatment19 to minimize and/or prevent mechanical pain.
There are many aspects of the physical therapy examination and intervention approach to osteomyoplastic transtibial amputation that require controlled study. Researchers have yet to determine the effect of absence of compression devices after osteomyoplastic amputation on patient function or time of recovery. Investigators have not examined the impact of end weightbearing on walking or other human performance measures. The functional potential of patients with osteomyoplastic transtibial amputation has yet to be determined—with and without comorbidity— and compared with those with standard amputation. In future studies, we aim to determine the amount and distribution of forces and muscle activity that actually occur inside the socket during standing, walking, stair climbing, and running. With controlled study, we may be able to allow patients to make informed, evidence-based choices between surgical approaches for amputation.