Total knee arthroplasty for neglected permanent post-traumatic patellar dislocation--case report

Surgical Treatment for Congenital Dislocation of the Patella in a Young Adult: A Case Report

CASE

We present an 18-year-old man with poor alignment of the lower limbs, marked by congenital dislocation of the left patella, with gait impairment, and an associated 20° flexion contracture. Surgical treatment was performed with a single complex procedure with the release of the lateral retinaculum, capsule, and iliotibial tract, followed by a subtraction trochleoplasty, tibial tubercle transfer, elongation of the quadriceps tendon, and anatomical reconstruction of the medial patellofemoral ligament. At the 5-year follow-up, the patient had a significant improvement in gait pattern, with the patella centered on the new trochlear groove without any signs of patellar instability.

CONCLUSIONS

The approach of congenital dislocation of the patella is controversial, and although numerous procedures have been described in children, the approach in adults should be individually tailored. In this case, trochlear deepening and preserving the trochlear cartilage proved to be an effective option for treating a congenital dislocation.

Total knee arthroplasty in patients with permanent patella dislocation. Report of two cases and literature review

The occurrence of permanent patellar dislocation associated with severe osteoarthritis is considered rare and difficult to treat. Literature: The literature is quite controversial on the subject. The objective of the study is to report two rare cases of severe osteoarthritis with permanent dislocation of the patella that underwent total knee arthroplasty, in addition to a review of the literature on the subject and related surgical technique. Total knee arthroplasty with using the medial parapatellar approach associated with lateral release was a good surgical option in patients with permanent patellar dislocation associated with advanced osteoarthritis.

Patellar instability treated with distal femoral osteotomy

BACKGROUND

Patellar instability can cause significant disability in both pediatric and adult patients, and it is associated with several factors including genu valgum. In this study, we describe the role of a lateral opening wedge distal femoral osteotomy (DFO) combined with lateral retinacular release in addressing genu valgum with associated patellar instability. The rationale for this approach is to medialize the patellar tendon insertion and decrease the Q angle with DFO.

METHODS

A consecutive series of patients were studied, and our outcomes of interest included improvements in radiographic measures and patient outcomes. Radiographic improvement was assessed using patella congruency angle (PCA), mechanical axis deviation (MAD), and lateral distal femoral angle (LDFA). Patient outcomes were assessed using Oxford Knee scores, KOOS-PS scores, VAS pain scores, and Kujala scores.

RESULTS

We studied eight patients (10 knees) that underwent a lateral opening wedge DFO for genu valgum and patellar instability. Mean follow-up duration was 27 months. PCA improved from 30.4° lateral preoperatively to 5.7° lateral postoperatively (p=0.016). Similarly, MAD improved from 33.1mm lateral to 6.5mm medial, and LDFA improved from 82.4° to 92.7° after surgery (p=0.002). There were significant improvements in VAS pain and Kujala scores after surgery (p<0.05), and a trend towards improvement in KOOS-PS scores (p=0.14). The mean Oxford Knee score at follow-up was 36.25.

CONCLUSION

There is an important relationship between mechanical alignment and patellar instability. Lateral opening wedge DFO is an effective treatment for patellar instability in patients with genu valgum.

The difficult primary total knee arthroplasty: a review

Primary total knee arthroplasty (TKA) is a reliable procedure with reproducible long-term results. Nevertheless, there are conditions related to the type of patient or local conditions of the knee that can make it a difficult procedure. The most common scenarios that make it difficult are discussed in this review. These include patients with many previous operations and incisions, and those with severe coronal deformities, genu recurvatum, a stiff knee, extra-articular deformities and those who have previously undergone osteotomy around the knee and those with chronic dislocation of the patella. Each condition is analysed according to the characteristics of the patient, the pre-operative planning and the reported outcomes. When approaching the difficult primary TKA surgeons should use a systematic approach, which begins with the review of the existing literature for each specific clinical situation.

Surgical treatment of congenital patellar dislocation in skeletally mature patients: surgical technique and case series

BACKGROUND

Congenital patellar dislocation is a rarely encountered condition and is readily treated in childhood to prevent lasting disability, knee pain, decreased range of motion and ambulation problems. This condition is very rarely seen in skeletally mature patients, and the treatment of the condition represents a challenge to the orthopedic surgeon.

SURGICAL TECHNIQUE AND METHODS

Patients were treated with soft tissue reconstruction and tibial tubercle transfer with or without a prior medial close-wedge distal femoral osteotomy, depending on the degree of valgus deformity. We, then, searched the database of our orthopedics center for cases of congenital patellar dislocation in skeletally mature patients who were surgically treated. We collected a total of five knees and analyzed the cases according to the type of surgery performed and difference between pre- and postoperative functions.

RESULTS

Five knees with congenital patellar dislocation were treated. The mean age of the patients was 29.6 years, and mean follow-up time was 4.3 years. Mean preoperative range of motion was 65°, and it increased to a mean of 105.5° after surgical treatment. The mean preoperative Kujala score was 29.2 and increased to 67.2 after surgical treatment.

DISCUSSION

Congenital patellar dislocations that are allowed to proceed to adulthood are difficult to treat, and surgical treatment depends on the degree of deformity of the patella and of the knee joint. This study shows that surgical treatment is able to correct the deformity and provide better knee function.

Patellar dislocation with genu valgum treated by DFO

Congenital habitual patellar dislocation is a rare condition of the knee where the patella dislocates during flexion and relocates during extension. The congenital form is permanent, irreducible, and presents at birth. It is characterized by a short quadriceps and a major patellofemoral dysplasia and short height. This article presents a rare case of a 27-year-old woman with recurring bilateral habitual dislocation of the patella after a failed previous proximal and distal realignment procedure. Clinical examinations of both knees revealed genu valgus knees and lateral joint pain that recurred after several previous operations. Radiographs of both knees showed patellar dislocation and genu valgum associated with patellofemoral dysplasia and osteoarthritis of the lateral compartment. Long-leg standing radiographs showed an anatomic tibiofemoral angle of right 13° and left 6° valgus and a mechanical tibiofemoral angle of right 8° and left 2° valgus and weight-bearing line of 65% on the right and 48% on the left. The authors performed a distal femoral closing wedging osteotomy to correct the valgus deformity, and then percutaneous lateral release and medial reefing were performed to stabilize the patellas of both knees simultaneously.

Total knee arthroplasty in a pseudoachondroplastic dwarfism patient with bilateral patellar dislocation

Late presentation of congenital patellar dislocation with advanced osteoarthritis is rare. This article presents a case of a 59-year-old man with underlying pseudoachondroplastic dwarfism. Advanced osteoarthritis due to bilateral neglected congenital patellar dislocation was treated with total knee arthroplasty without patella relocation surgery. Two years later, the patient had an improvement in Knee Society scores, painless function, and stability.

Posttraumatic chronic patellar dislocation treated by distal femoral osteotomy and medial patellofemoral ligament reconstruction

Chronic patellar dislocation is a rare condition where the patella remains dislocated throughout knee range of motion during flexion and extension. In adults, the delayed presentation of this condition is often due to symptoms caused by the onset of severe secondary osteoarthritis. To the authors' knowledge, all of the cases reported in the literature have been treated by patellofemoral or total knee replacements depending on patient age and the extent of the arthritis. This article describes a rare case of a 22-year-old woman who sustained a traumatic chronic patellar dislocation for 5 months. Clinical examination revealed a valgus deformity of the left leg secondary to childhood injury and that the patella lay lateral to the lateral femoral condyle throughout flexion and extension. Radiographs of the knee revealed patellar dislocation. Long-leg radiographs of the left leg showed an anatomic tibiofemoral angle of 17° valgus. The anatomical (74°) and mechanical (80°) lateral distal femoral angles were abnormal, whereas the medial proximal tibial angle (87°) was normal, confirming that the valgus deformity was due to the abnormal distal femur. The authors performed a distal femoral osteotomy to correct the valgus deformity. Medial patellofemoral ligament reconstruction using a hamstring autograft was performed to stabilize the patella.

Surgical treatment for permanent dislocation of the patella in adults

Permanent dislocation of the patella in adults is a rare condition that presents with complete irreducible lateral dislocation of the patella, combined with secondary changes, such as valgus deformity and leg-length discrepancy. Because these secondary changes cannot heal spontaneously after skeletal maturation if left untreated, the patients frequently possess pathology not limited to the knee joint and extending to the whole lower extremity, such as malalignment or leg-length discrepancy, that can develop into osteoarthritis of the knee. However, to our knowledge, few surgeons advocate the significance of correcting the malalignment in treating adult patients. We treated a 34-year-old woman with permanent dislocation of the patella in a 2-stage surgery, consisting of first-stage correction of valgus deformity and limb shortening using a Ilizarov external fixator and second-stage realignment of the dislocated patella over the trochlea. A follow-up examination conducted 3 years after the second operation revealed plantigrade gait with normal alignment of the lower extremity without limping and medial thrust. The patella was tracking centrally in the patellofemoral groove. Radiographs showed a neutral mechanical axis of the lower extremity, no evidence of patellar subluxation, and no deteriorating osteoarthritic changes at the tibiofemoral joint. This case highlights the importance of correcting secondary changes, such as valgus deformity and leg-length discrepancy, to reduce the risk of future osteoarthrosis and postoperative dislocation, especially when these deformities are substantial.

Total knee arthroplasty in a patient with neglected congenital patellar dislocation

Late presentation of congenital patellar dislocation with advanced osteoarthritis is rare. This article presents a case of 56-year-old woman with advanced osteoarthritis due to right neglected congenital patellar dislocation treated with total knee arthroplasty (TKA) with release of the lateral retinaculum and proximal extensor mechanism realignment. One year later, the patient had improvement of her Knee Society scores and painless function, stability, and better extensor strength. A literature search revealed a limited number of similar cases in which congenital patellar dislocation was treated with TKA. Total knee arthroplasty provides a valid treatment option for adults with congenital patellar dislocation who have absence of the femoral sulcus and associated osteoarthritis. Total knee arthroplasty has the ability to correct the pathologies seen with congenital patellar dislocation, eg, external tibial rotation, absence of femoral groove, and patellar hypoplasia. Realignment of extensor mechanism restores quadriceps strength, normal knee biomechanics, and may prevent complications such as dislocation.

TKA using the subvastus approach and lateral retinacular release in patients with permanent post-traumatic patellar dislocation: a report of two cases

Permanent post-traumatic patellar dislocation is a rare condition, and total knee arthroplasty (TKA) can be performed for osteoarthritic knees with this condition. There have been only a few reports about using the standard medial parapatellar approach and extensive lateral release or extensor mechanism realignment for patients with permanent post-traumatic patellar dislocation. We performed two TKAs with using a subvastus approach and lateral release for osteoarthritic knees with permanent post-traumatic patellar dislocation. The patients were well satisfied with their results. The patellae tracked very well in the femoral trochlear groove throughout the full range of motion after the operations. Bone scans were done 1 year postoperatively on both patients, and the scans showed normal vascularity for the patella.

Permanent patellar dislocation and osteoarthritis of the knee after femoral fracture in childhood. A case report

A 52 year-old woman suffered bilateral femoral shaft fractures when she was 5 years old and they were treated surgically. She had been able to walk without pain and giving way throughout her young and adult life, however, when she came to us with a 1-year history of the right knee pain, she could walk only 10 m continuously. The right knee revealed valgus deformity with complete lateral patellar dislocation. The femoro-tibial angle was 154 degrees and arthritic change was seen in the femorotibial joint. Surfaces of both the patella and the femur were degraded. Twenty-two degrees of rotational deformity was also found internally in the involved side. Varus osteotomy with external rotation of the distal fragment and lateral retinacular release combined with reefing of vastus medialis muscle were performed. Twenty-four months after surgery, knee score and functional score were, respectively, 85/100 and 71/100, using knee society clinical rating system and there was no pain associating patella incongruity.

Knee arthrodesis using circular external fixator in the treatment of infected knee prosthesis: case report

A patient (68 years old and male) underwent total knee replacement because of arthrosis, but he subsequently had infection due to a wound problem. Although he underwent early debridement, antibiotherapy, and soft-tissue operation, treatment failed because of improper soft-tissue coverage and progression of the infection. Therefore, the prosthesis was removed and a spacer with antibiotic was placed, in order to provide soft-tissue coverage and to eradicate infection. After 2 months, the patient underwent knee arthrodesis using a circular external fixator to achieve a stable lower extremity and to facilitate return to activities of daily living. We obtained knee fusion at 4 months without any requirement for secondary procedure of soft tissue and bone graft. There was no major complication. Arthrodesis with circular external fixator is a reliable and successive method that should be preferred for the treatment of infected knee replacement.