Long term results of excision arthroplasty of the canine hip

Contribution to the Study of Perioperative Factors Affecting the Restoration of Dog's Mobility after Femoral Head and Neck Excision: A Clinical Study in 30 Dogs

This study aimed to compare postoperative analgesia and the time of limb weight bearing induced by the intraoperative administration of a local anesthetic at the site of the femoral head and neck excision (FHNE) in dogs, with and without the administration of preoperative epidural anesthesia. Additionally, the impact of postoperative opioid drug administration on weight-bearing time was examined. This randomized, blinded, prospective clinical study included 30 client-owned dogs. The dogs were randomly divided into three groups (A, B, C), each further divided into two subgroups (A1, A2, B1, B2, C1, C2). Group A received epidural anesthesia and ropivacaine at the ostectomy site, Group B received only ropivacaine, and Group C served as the control group. Subgroup 1 received a non-steroidal anti-inflammatory drug postoperatively, while Subgroup 2 had tramadol added to their regimen. Pain assessment was conducted using the University of Melbourne Pain Scale (UMPS) and an algometer. The study concluded that multimodal analgesia, utilizing all the aforementioned analgesic techniques, resulted in faster limb weight bearing for dogs undergoing FHNE.

Effect of Femoral Head and Neck Osteotomy on Canines’ Functional Pelvic Position and Locomotion

The long-term effect of femoral head and neck osteotomy (FHO) on the locomotory system of dogs was evaluated. The study comprised an owner questionnaire and an orthopaedic examination, anatomical measurements, and pressure-sensitive walkway analysis for dogs. Linear mixed effect models were used for statistical analysis. Ten dogs with a median of 2.5 years since their unilateral FHO were included. According to the questionnaire results, nine dogs had returned to a normal physical activity level. Muscle atrophy (p = 0.005), less extension in the coxofemoral joint (p = 0.003), and less static weight bearing on the FHO limb (p = 0.003) were observed. No consistent pattern regarding tilt or position of the pelvis was noted when measuring height of the tuber ischii (p = 0.39). Five of the dogs tilted away from, and five towards the FHO side when measured from the tuber sacrale with a Myrin goniometer. No differences regarding stance time, swing time, or peak pressure between the FHO and non-FHO limb were seen in trot (p = 0.70, p = 0.26, and p = 0.91, respectively). Over the long term, the FHO limb has muscle atrophy, decreased coxofemoral extension, and decreased static weight bearing. However, this does not seem to affect the trot of the dogs. Dog owners considered the outcome of surgery to be good or excellent.

Use of clinical and computed tomography findings to assess long-term unsatisfactory outcome after femoral head and neck ostectomy in four large breed dogs

Femoral head and neck ostectomy (FHNO) is a salvage surgical procedure intended to eliminate hip joint laxity associated pain in the immature dog, or pain due to secondary osteoarthritis in the mature dog. The outcome of the procedure is associated with the size of the dog but the cause of a generally poorer outcome in larger breeds has not been determined. The objective of this study was to assess the long-term results of FHNO associated with unsatisfactory functional outcome by means of clinical examination and computed tomography (CT) scanning. Four large mixed breed dogs underwent FHNO in different veterinary clinics. Clinical and CT scanning evaluations were carried out long time after the procedures had been done. Hip pain, muscle atrophy, decreased range of motion and chronic lameness were observed at clinical examination. Extensive remodelling, unacceptable bone-on-bone contact with bony proliferation involving the femoral neck and acetabulum, but also excessive removal with bone lysis were observed by CT scanning. Revision osteotomy was performed in one dog. Deep gluteal muscle interposition was used, but no improvements were observed postoperatively. This is the first report on the evaluation of three-dimensional CT reconstructions of the late bone remodelling associated with poor clinical outcome in large dogs. The study shows that FHNO could lead to severe functional deficits in large breed dogs. An extensive follow-study is necessary to more accurately determine the frequency of such complications.

Use of computed tomography to compare two femoral head and neck excision ostectomy techniques as performed by two novice veterinarians

Objectives: To compare the results of femoral head and neck excision (FHNE) ostectomy performed by two novice veterinarians using an osteotome and mallet or microsagittal saw.

Methods: In this ex vivo cadaveric study, hindlimbs of eight canine cadavers were randomized to FHNE with osteotome or micro sagittal saw as performed by two recently graduated veterinarians. The hindimbs were imaged by computed tomography (CT) before and after the osteotomy. Post FHNE CT images were evaluated by a board certified radiologist blinded to the ostectomy technique for assessment of the number of bone fragments, fissures, smoothness of osteotomy margination, and volume of residual fe-moral neck.

Results: Femoral head and neck excision performed with the osteotome produced more peri-ostectomy bone fragments, cortical fissures, irregular margins, and residual femoral neck volume, compared with osteotomy using a saw.

Clinical relevance: Compared to FHNE performed with a sagittal saw, osteotome FHNE resulted in a greater bone trauma and residual neck bone volume, which would require post-ostectomy modification in a clinical setting.

Feline hip dysplasia

Practical relevance:

The reported incidence of hip dysplasia (HD) in cats varies dramatically between studies, but the condition is likely more common than we realise. There is little doubt that cats with HD and associated osteoarthritis (OA) suffer pain, and this warrants appropriate therapy.

Diagnostic challenges:

Clinical signs of HD in cats are often gradual in onset, making them difficult to appreciate, but may include inactivity, pelvic limb lameness, difficulty jumping and climbing stairs, and reluctance to squat to defecate. Often lameness is bilateral, and can be particularly difficult to recognise. The most common radiographic finding is an abnormally shallow acetabulum. Subluxation, however, is not consistently associated with OA in cats and therefore the role that joint laxity plays in disease progression remains uncertain. Degenerative changes of the femoral head and neck seem to develop later than in the dog, and are less marked.

Therapeutic challenges:

The majority of cats respond to non-surgical management with environmental modulation, physical therapy, dietary modulation, weight loss, nutraceuticals and drug therapy. Should non-surgical management not provide sufficient relief, two salvage surgical options are available: femoral head and neck excision (FHNE) and total hip replacement (THR). While there is a risk of complications with micro-THR, the positive outcomes that have been reported indicate that it should be considered in the treatment of coxofemoral pathology in cats in the same way that THR is considered for larger dogs, especially given the inconsistent results associated with FHNE. Monitoring the effect of treatment is challenging as the assessment of pain in cats is complex and there is no validated scoring system or owner-completed questionnaire yet available for cats.

Evidence base:

There is a paucity of clinical reports focusing solely on HD in cats. The author draws on a combination of published studies, in cats, dogs and humans, as well as personal clinical experience.

Treatment of hip dysplasia

Hip dysplasia is a common orthopaedic developmental disorder of dogs. This paper reviews the treatment options available for management of the condition in the skeletally immature and adult dog.

Micro total hip replacement for dogs and cats: surgical technique and outcomes

OBJECTIVE

To describe the surgical technique for the micro total hip replacement (Micro THR) system and report clinical outcomes.

STUDY DESIGN

Prospective study.

ANIMALS

Dogs (n=49) and cats (n=8) with coxofemoral arthropathy.

METHODS

Small breed dogs and cats with coxofemoral arthritis were enrolled for Micro THR. Patient data were recorded. Implant positioning and cement mantle quality were evaluated radiographically. Orthopedic examinations and client interviews were used to assess outcome.

RESULTS

Micro THR was performed unilaterally (40 dogs, 8 cats) and staged bilaterally (9 dogs) to resolve pain associated with osteoarthritis or trauma. Mean body weight was 7.2 kg. Postoperative complications included prosthesis luxation (9), cup aseptic loosening (1), and sciatic neurapraxia (1). Mean radiographic follow up was 96.1 weeks; 10 joints were followed for ≥3.0 years. Sixty of the 66 (91%) Micro THRs had excellent outcomes. Two dogs (<2.75 kg) were too small for the prosthesis and 4 dogs with unmanageable luxation had explantation.

CONCLUSIONS

Micro THR is considered a satisfactory procedure for management of small breed dogs and cats with coxofemoral disease unresponsive to medical management.

CLINICAL RELEVANCE

Micro THR is a viable option to treat disabling disorders of the hip. More than 170 cat and small dog breeds, and many mixed breeds, could benefit from Micro THR surgery.

Excision arthroplasty of the hip joint in dogs and cats

From 1978 to 1989, 132 dogs and 51 cats underwent femoral head and neck ostectomy at the Department of Veterinary Surgery, Ludwig-Maximilians University, Munich, Germany. Clinical and radiographic re-evaluations were carried out an average of four years postoperatively in 81 (44%) of the animals, and gait analysis was also done in 17. The functional results were rated good in 38% of patients, satisfactory in 20%, and poor in 42%. However 96% of the owners were satisfied with the results. Kinetic and kinematic measurements showed that although femoral head and neck resection alleviated pain, it resulted in functional deficits in small as well as large breed dogs. These deficits were not visible during rapid movement.

This article was originally published in 1997 in the journal Tierärztliche Praxis. Both authors have approved the re-publication of this article in English, for which they have provided the translation of as well. Original citation: Off W, Matis U. Resektionsarthroplastik des Hüftgelenkes bei Hunden und Katzen. Klinische, röntgenologische und ganganalytische Erhebungen an der Chirurgischen Tierklinik der Ludwig-Maximilians-Universität München. Tierärztl Prax 1997 25: 379–387.

Effects of femur position on radiographic assessment of completeness of femoral head and neck excision in medium- to large-breed dogs

OBJECTIVE

To determine the effect of femur positioning on radiographic assessment of completeness of excision after femoral head and neck excision (FHNE) in medium to large breed dogs.

SAMPLE POPULATION

10 femurs from canine cadavers (body weight > 20 kg).

PROCEDURE

Complete FHNE was performed on 5 canine femurs. Excision consisting of inadequate removal of the medial distal aspect of the femoral neck was performed on the remaining 5 femurs. Each femur was positioned with predetermined amounts of internal and external rotation about the long axis and radiographed. Investigators evaluated a set of 8 radiographic views of each femur. Sensitivity (SE), specificity (SP), positive predictive value, negative predictive value, and completeness of excision assessment accuracy were estimated for each of the femur positions.

RESULTS

Craniocaudal radiographic views of the femur positioned with external rotation of 15 degrees, 30 degrees, and 45 degrees as a group had the highest SE, SP, and completeness of excision assessment accuracy relative to other radiographic views. The SE, SP, and accuracy of assessment were higher when the degree of external rotation was increased from 15 degrees to 30 degrees or 45 degrees.

CONCLUSIONS AND CLINICAL RELEVANCE

Craniocaudal radiographic views of the femur positioned in external rotation (15 degrees, 30 degrees, and 45 degrees) improved the ability to detect adequacy of excision relative to standard craniocaudal and lateromedial radiographic views. Evaluation of craniocaudal radiographic views of the femur positioned in external rotation may increase the ability to assess FHNE adequacy in medium- to large-breed dogs.

Results of arthroscopic versus open arthrotomy for surgical management of cranial cruciate ligament deficiency in dogs

OBJECTIVE

To evaluate postoperative morbidity in dogs after experimental cranial cruciate ligament transection and immediate stifle stabilization using an arthroscopically assisted or open arthrotomy technique.

STUDY DESIGN

Experimental, prospective study.

ANIMALS

Thirteen mature, healthy dogs.

METHODS

Dogs were randomly assigned to 1 of 2 groups. Seven underwent open arthrotomy while 6 underwent arthroscopy of 1 stifle joint. Cranial cruciate ligaments were transected and debrided and all stifles were stabilized using 2 lateral extracapsular fabellar-tibial sutures. Minimally invasive suture placement was employed in the arthroscopy group. All animals were evaluated for 9 weeks using kinetic gait assessments, comfortable stifle range of motion measurements, thigh girth measurements, differential cell counts of synovial fluid, and subjective scores of behavior, limb use, and lameness.

RESULTS

Significant differences in postoperative morbidity were observed during the 9-week postoperative period. Greater peak vertical force for 8 weeks (P=.015), vertical impulse for 6 weeks (P=.044), comfortable stifle range of motion for 9 weeks (P=.017), comfortable stifle flexion for 4 weeks (P=.005), and operative limb thigh circumference (P=.020) for 9 weeks were observed for the arthroscopy group. A trend towards a lower differential mean synovial polymorphonuclear cell count in the arthroscopy group was seen at 4 and 8 weeks postoperatively. No differences in subjective evaluation scores were noted.

CONCLUSIONS

In this study population, significant differences were seen between the arthroscopy and arthrotomy groups for peak vertical force, vertical impulse, comfortable stifle range of motion, comfortable stifle flexion, and thigh circumference data.

CLINICAL RELEVANCE

The results of this study suggest that short-term postoperative morbidity may be reduced in dogs receiving arthroscopic joint surgery with a limited approach for stifle stabilization as compared with a traditional open arthrotomy technique.

Effects of postoperative administration of ketoprofen or carprofen on short- and long-term results of femoral head and neck excision in dogs

OBJECTIVE

To determine whether postoperative administration of ketoprofen or carprofen had any effects on short- or long-term results of femoral head and neck excision (FHNE) in dogs.

DESIGN

Prospective randomized controlled trial.

ANIMALS

40 client-owned, large-breed dogs undergoing FHNE and 15 healthy large-breed dogs used as controls for hip joint angle measurements and force plate analyses.

PROCEDURE

Dogs undergoing FHNE were treated with ketoprofen, carprofen, or a placebo for 21 days after surgery. Hip joint abduction and extension angles were measured at the end of surgery and 120 days later. Lameness scores were assigned, and force plate analyses were performed on days 3, 15, and 120.

RESULTS

There were no significant differences among treatment groups in regard to hip joint angles or lameness scores. Force plate analysis revealed that dogs in all 3 treatment groups bore consistently less weight on the operated limb than did control dogs for the duration of the study. Dogs receiving ketoprofen had greater peak propulsive force at a walk on day 3 and greater peak vertical force at a walk on day 15 than did dogs receiving the placebo. Treatment of an acute condition and preservation of the lesser trochanter, but not postoperative analgesic administration, were positively associated with ground reaction forces on day 120. Owners of 12 of 31 dogs indicated that the dog's gait worsened for a few days after discontinuation of analgesic administration.

CONCLUSIONS AND CLINICAL RELEVANCE

Administration of ketoprofen or carprofen after surgery was not associated with long-term results of FHNE, probably because of the impact of other factors. Because some owners noticed worsening of the lameness following cessation of analgesic administration in the present study, it is possible that longer administration would have improved long-term results.

Retrospective analysis of canine miniature total hip prostheses

OBJECTIVE

To determine the practicality and clinical outcome of miniature total hip replacement (THR) in dogs.

STUDY DESIGN

Retrospective study. Sample Population- Seventeen client-owned dogs that had miniature THR.

METHODS

Patient data surveyed included signalment, body weight, diagnosis, implant size, surgical technique, and intraoperative and postoperative complications. Radiographic evaluation included angle of lateral opening of the acetabular component, implant positioning, cement mantle quality, and femoral displacement measurement and ratio. Client questionnaire and orthopedic examination were used to obtain long-term follow-up information.

RESULTS

Miniature THR was performed to address hip dysplasia and secondary osteoarthritis. In 1 dog, a staged bilateral procedure was performed. Mean body weight was 19 kg (range, 12 to 25 kg). Penetration or fissure of the femoral cortex was the most common intraoperative complication and occurred in 3 dogs. In 3 dogs, there was excessive coxofemoral laxity after reduction of the prosthesis. This instability was addressed specifically in 2 dogs by capsulorrhaphy or capsular prosthesis. Postoperative convalescent complications (craniodorsal luxation, 2 dogs; acetabular cup displacement, 1 dog) were related to surgical errors. Aseptic loosening of the femoral implant was diagnosed in 1 dog at 18 months. Mean follow-up time was 17 months (range, 4 to 42 months). Fifteen of 18 (83%) miniature THRs had good or excellent outcomes.

CONCLUSIONS

Miniature THR should be considered a satisfactory alternative to femoral head and neck ostectomy in medium-size dogs affected by hip dysplasia and secondary osteoarthritis. The population of medium-size dogs that might derive more benefit from THR than FHO has yet to be defined.

CLINICAL RELEVANCE

Miniature THR is a viable treatment option in medium-size dogs with hip dysplasia.

Removal of infected canine cemented total hip prostheses using a femoral window technique

OBJECTIVE

To evaluate a femoral window technique for retrieval of cemented total hip prostheses.

STUDY DESIGN

Retrospective clinical study.

ANIMALS

Twelve dogs with infection of a cemented modular total hip prosthesis.

METHODS

Implant removal was performed by an extended craniolateral approach to the hip and proximal femur without trochanteric osteotomy. The femoral cement mantle was fragmented and removed with simple orthopedic instrumentation by a lateral femoral window that was repaired using cerclage wires. Surgical technique, intraoperative and postoperative complications, bacterial culture results, histopathologic findings, and completeness of cement removal were recorded. Follow-up radiographs were taken 5 to 9 weeks postoperatively. Long-term follow-up information was obtained by client questionnaire. Functional outcome was assessed by scoring ability to stand, sit, walk, run, play, climb stairs, and get into a car.

RESULTS

Prosthesis retrieval was performed 2 to 41 months after implantation (median, 14 months). Complete removal of femoral cement was achieved in 10 dogs. A nondisplaced femoral fissure, extending proximally from the window, was an intraoperative complication in 2 dogs. Staphylococcus spp was most commonly isolated (6 dogs) from interfacial membrane samples. Systemic antibiotic therapy, dependent on susceptibility testing, was administered for 3 to 10 weeks postoperatively. There was radiographic evidence of osteotomy healing at 5- to 9-week reassessment. Recurrence of osteomyelitis was not observed. Long-term functional outcome was considered mildly abnormal.

CONCLUSIONS

The lateral window was an effective technique for retrieval of retained femoral cement.

CLINICAL RELEVANCE

Removal of an infected prosthesis using this technique generally resulted in a clinical outcome comparable to that with ab initio femoral head and neck excision.

Surgical treatment of osteoarthritis

Surgical treatment of OA is appropriate when conservative therapy fails or is inadequate. The veterinary orthopedist's goals in treatment should be to alleviate pain, maintain function, and prevent or remove the potential for further degeneration of the joint. Currently, in veterinary surgery, THR and femoral head and neck excision are the primary treatments for OA of the coxofemoral joint. Other joints are treated primarily by arthrodesis or excision arthroplasty. Arthroscopy is proving to be a valuable tool in the diagnosis and treatment of OA, and total stifle and elbow replacement and cartilage resurfacing through chondrocyte grafting are on the horizon as potential treatment options.

Femoral head and neck excision in the management of canine hip dysplasia

Degenerative joint disease as a sequela to pathology of the coxofemoral joint can cause considerable pain. In dogs weighing less than 20 km, excision of the femoral head and neck is sufficient to control this pain. A pseudoarthrosis functions effectively as a salvage hip joint. In dogs weighing more than 20 km, additional surgery is required to ensure painfree use of the hip. Postoperatively, the weight of these larger animals appears to cause striking of the proximally excised femoral shaft with the pelvis during exercise. This contact causes pain that limits the use of the joint. The inclusion of a biceps femoris muscle sling to prevent this striking and the resultant pain is outlined.

Effect of two muscle sling techniques on early morbidity after femoral head and neck excision in dogs

Femoral head and neck excision was performed on the left coxofemoral joint of 18 dogs. The osteotomy site was padded with a partial-thickness biceps femoris muscle sling in one group of six dogs, and with a deep gluteal muscle flap in another group of six dogs. In a third group of six dogs, a partial-thickness biceps flap was created and sutured back in its original location. The dogs were monitored daily for 3 weeks for degree of lameness, range of motion, fever, and postoperative complications. Dogs with intra-articular muscle pads were less lame and had a greater range of motion in the treated hip than dogs without intra-articular muscle pads. Dogs with biceps slings showed more improvement in limb function and range of motion than did dogs with deep gluteal flaps. There were no significant differences in mean temperature elevations and no clinically significant postoperative complications. Use of a partial-thickness biceps muscle sling or a deep gluteal muscle flap decreased the chances of early postoperative morbidity and provided an earlier return to function. The partial-thickness biceps sling appeared to be more beneficial than the deep gluteal flap.

A retrospective study of 100 pelvic fractures in horses

The records of 100 horses with clinical or radiographic diagnosis of a pelvic fracture were reviewed to determine prognostic indicators associated with clinical signs or radiographic fracture characteristics. Degree of lameness, soft tissue swelling, crepitis, muscle atrophy, skeletal external assymetry and palpable assymetry on rectal examination were evaluated. There was no significant relationship between the aforementioned clinical signs and the long-term cause outcome. Fracture sites or presence of an acetabular fracture were not related to prognosis. The positive outcome of 77 per cent of horses that were allowed to survive and were available for follow-up in this study warrants the effort of salvage of valuable individuals.

Postoperative examination of the biceps femoris muscle sling used in excision of the femoral head and neck in dogs

Twenty-four dogs underwent unilateral excision of the femoral head and neck. An adjunctive biceps femoris muscle sling procedure was done in 16 dogs. In eight dogs (controls), the flap was dissected and returned to its original position. Four dogs with muscle slings were euthanatized on days 2, 5, 30, and 60, respectively. Four control dogs were euthanatized on day 2 and four dogs on day 5. Limb function did not differ consistently between dogs with muscle slings and control dogs. There was marked swelling and edema of the affected limb in half the dogs with muscle slings but not in the controls. Postoperative temperature elevations were significantly higher in dogs with muscle slings on days 1 and 2 (p less than 0.05). Infection was documented in four dogs with muscle slings. Flaps from control dogs had only minor gross and histologic abnormalities. On days 2 and 5, flaps from dogs with muscle slings appeared congested and swollen beneath and distal to the ostectomy site, with infarction involving 50 to 90% of the muscle mass. On days 30 and 60, the muscle slings were atrophic and fibrous, and by day 60 a synovial membrane covered the surfaces of all slings within the pseudarthrosis. Muscle fiber loss was attributed to infarction, necrosis, and disuse atrophy.

A retrospective comparison of three techniques for femoral head and neck excision in dogs

Femoral head and neck excision was performed in 169 dogs over a 7 year period. A written questionnaire completed by 56 owners, evaluating a total of 72 joints, was the basis for retrospective evaluation of the efficacy of the procedures used. There were four surgical groups: femoral head and neck excision (FHNE) in dogs with body weights over 14 kg, the same procedure in dogs with body weights less than 14 kg (SMALL), femoral head and neck excision with muscle interposition (MI), and the wedge resection technique (WRT). Although differences in results were noted, there were no statistically significant differences between any of the groups for the percentage of leg use during normal activity (p greater than 0.05), mean postoperative time until leg use, use of the leg or hopping while running, or lameness with exercise (p greater than 0.10). The results of this study suggest that there is little advantage in performing the more time-consuming and traumatic muscle interposition and wedge resection procedures.

Excision arthroplasty of the femoral head and neck

An abnormality of the coxofemoral joint is recognized when the articular cartilage sliding interface between the femoral head and the acetabulum is interrupted. The article considers the pathologic conditions that may affect the normal coxofemoral articulation and are responsive to excision arthroplasty. Techniques of excision arthroplasty and the biceps femoris muscle sling technique are described.

Total hip replacement

Total hip replacement in the dog has proved to be a highly successful method of restoring normal, pain-free motion to the coxofemoral joint. In a prospective study done at The Ohio State University College of Veterinary Medicine and the Berwyn Veterinary Associates Hospital, the indications and contraindications, the most effective surgical technique, the complication rate, and the long-term functional evaluation have been established for canine total hip replacements. This study has established that a 95 per cent success rate for function of the hip joint can be achieved if the established guidelines are followed.

A comparison of standard femoral head and neck excision and femoral head and neck excision using a biceps femoris muscle flap in the dog

Sixteen normal 20 to 30 kg dogs had standard femoral head and neck excision (8 dogs) or femoral head and neck excision with interposition of a biceps muscle flap (8 dogs). Lameness lessened at week 6, and did not differ between groups; neither group returned to a completely normal gait. Weightbearing decreased on the operated pelvic limb compared to controls (forceplate analysis). Weightbearing force of the muscle flap dogs was significantly less at weeks 6 and 16 than that of the standard femoral head and neck excision dogs. The operated limb of both groups was shortened; shortening was significantly greater for the muscle flap group. Hip extension was limited in both groups. Both groups had decreased (more acute) hip, stifle, and hock angles measured in standing position. Thigh muscle atrophy was more pronounced in the muscle flap group at week 6. More soft tissue was interposed in the muscle flap group at necropsy compared to the group with standard femoral head and neck excision, but the difference was not statistically significant. Skeletal muscle fibers were present in the interposed fibrous connective tissue of the muscle flap group, and the healed surfaces were smoother than those of the standard femoral head and neck excision group.