A stand-alone lateral condyle-elevating trochlear osteotomy leads to high residual instability but no excessive increase in patellofemoral osteoarthritis at 12-year follow-up.

PURPOSE AND HYPOTHESIS: Trochlear osteotomy is a rarely performed procedure, only indicated in selected cases. Due to its nature, it can potentially lead to cartilage damage and subsequent early osteoarthritis. Satisfactory short-term results from lateral condyle-elevating osteotomy have previously been reported. The long-term effects of this procedure on clinical outcomes, patellar stability and radiological osteoarthritis are reported here. METHODS: Sixteen patients (19 knees) with patellar instability due to trochlear dysplasia were included. An isolated lateral condyle-elevating trochlear osteotomy was performed between 1995 and 2002. All patients were re-examined at a minimum of 12-year follow-up. Three patients were lost to follow-up, and one patient underwent a patellofemoral arthroplasty 3 years post-operatively due to progressive osteoarthritis. Complete follow-up was therefore available in 12 patients (15 knees). Recurrent instability, VAS pain, WOMAC, Lysholm and Kujala scores were used as outcome measures. Radiological osteoarthritis was recorded using the Iwano and the Kellgren-Lawrence classifications. A repeated-measures ANOVA was used to test for repeated measures (pre-operative, 2-year and final follow-up), and Spearman's correlation coefficient for relationships between osteoarthritis and functional scores. RESULTS: At final follow-up, VAS pain showed a non-significant improvement from 52 to 25, and the median Kujala score was 78. Median Lysholm (54-71, p = 0.021) and WOMAC (78-96, p = 0.021) scores improved from the pre-operative assessment to final follow-up. There was no significant difference observed between clinical scores at the 2-year and final follow-up. Residual patellar instability was reported in four out of 15 knees. Three knees showed no patellofemoral osteoarthritis, eight knees had grade 1 and four knees grade 2. No correlation between VAS pain, Lysholm, WOMAC or Kujala scores and osteoarthritis could be identified (n.s.). CONCLUSION: A stand-alone lateral condyle-elevating trochleoplasty results in the significant improvement of most clinical scores; however, when performed as a stand-alone procedure, it leads to a high percentage of residual instability. In contrast to general belief, the development of patellofemoral osteoarthritis at 12-year follow-up did not exceed the findings from other trochleoplasty case series. LEVEL OF EVIDENCE: Case series with no comparison group, Level IV.

Radiological characteristics of the knee joint in nail patella syndrome.

AIM: Nail patella syndrome (NPS) is a skeletal dysplasia with patellofemoral dysfunction as a key symptom. We present the first in-depth radiological evaluation of the knee in a large series of NPS patients and describe the typical malformations. PATIENTS AND METHODS: Conventional radiological examination of 95 skeletally mature patients with NPS was performed. Patellar morphology was classified according to the Wiberg classification as modified by Baumgartl and Ficat criteria, and trochlear shape was classified according to the Dejour classification. RESULTS: Patellar aplasia was present in 4/90 (4%), and patellar hypoplasia in 77/90 (86%) of patients. The prevailing patellar shapes were type III, type IV and Hunter's cap. No patellar shape genotype-phenotype association could be found. The malformations of the distal femur comprised shortening of the lateral femoral condyle in 46 out of 84 patients (55%), with a prominent anterior surface of the lateral femoral condyle in 47 out of 84 patients (56%) and a flat anterior surface of the medial femoral condyle in 78 out of 85 patients (92%). The trochlea was type A1 according to the Dejour classification in 79 out of 85 patients (93%). CONCLUSION: An easily recognisable characteristic quartet of malformations consisting of patellar aplasiaor hypoplasia and the malformations of the distal femur was found in 22 out of 81 patients (27%), with the majority displaying at least three malformations. TAKE HOME MESSAGE: The distinct malformations of the knee in nail patella syndrome are easily recognisable on conventional radiographs and lead to the correct interpretation of the aberrant morphology which is essential in the treatment of these patellofemoral disorders.

A self-centring osteotomy of the tibial tubercle for patellar maltracking or instability: results with ten-years' follow-up.

An increased tibial tubercle-trochlear groove (TT-TG) distance is related to patellar maltracking and instability. Tibial tubercle transfer is a common treatment option for these patients with good short-term results, although the results can deteriorate over time owing to the progression of osteoarthritis. We present a ten-year follow-up study of a self-centring tibial tubercle osteotomy in 60 knees, 30 with maltracking and 30 with patellar instability. Inclusion criteria were a TT-TG ≥ 15 mm and symptoms for > one year. One patient (one knee) was lost to follow-up and one required total knee arthroplasty because of progressive osteoarthritis. Further patellar dislocations occurred in three knees, all in the instability group, one of which required further surgery. The mean visual analogue scores for pain, and Lysholm and Kujala scores improved significantly and were maintained at the final follow-up (repeated measures, p = 0.000, intergroup differences p = 0.449). Signs of maltracking were found in only a minority of patients, with no difference between groups (p > 0.05). An increase in patellofemoral osteoarthritis was seen in 16 knees (31%) with a maximum of grade 2 on the Kellgren-Lawrence scale. The mean increase in grades was 0.31 (0 to 2) and 0.41 (0 to 2) in the maltracking and instability groups respectively (p = 0.2285) This self-centring tibial tubercle osteotomy provides good results at ten years' follow-up without inducing progressive osteoarthritis.

Effect of medial-lateral malpositioning of the femoral component in total knee arthroplasty on anterior knee pain at greater than 8 years of follow-up.

BACKGROUND: The trochlea is often medialized after total knee arthroplasty (TKA) resulting in abnormal patellar tracking, which may lead to anterior knee pain. However, due to the difference in shape of the natural trochlea and the patellar groove of the femoral component, a medialization of the femoral component of 5 mm results in an equal patellar position at 0-30° of flexion. We tested the hypothesis that more medialization of the trochlea results in a higher VAS pain score and lower Kujala anterior knee pain score at midterm follow-up. METHODS: During surgery a special instrument was used to measure the mediolateral position of the natural trochlea and the prosthetic groove in 61 patients between 2004 and 2005. Patient reported outcome measures were used to investigate the clinical results (NRS-pain, NRS-satisfaction, KOOS-PS and Kujala knee score). RESULTS: In total 40 patients were included. The mean follow-up was 8.8 years. A medialization of ≥5 mm resulted in a significantly lower NRS-pain (0.2 vs. 1.4; p=0.004) and higher NRS-satisfaction (9.6 vs. 8.2; p=0.045). Overall clinical results were good; KOOS-PS was 33.9 and Kujala knee score was 72.1. CONCLUSIONS: The present study showed that a more medial position may result in a better postoperative outcome, which can probably be explained by the non-physiological lateral orientation of the trochlear groove in TKA designs. LEVEL OF EVIDENCE: Level III.

Patellofemoral evaluation with magnetic resonance imaging in 51 knees of asymptomatic subjects.

PURPOSE: The objective of this study is to evaluate patellofemoral joint imaging on magnetic resonance imaging (MRI) in asymptomatic subjects to assess normal values and to test statistical correlation and reliability of MRI scan. METHODS: An analysis of 51 standard MRI examinations was performed. Sulcus angle (SA), patellar axis (PA), lateral patellofemoral angle (LPFA), and lateral patellofemoral length (LPL) were measured. None of the patients suffered from patellofemoral complaints. Patients with patella alta and significant hydrops were excluded. The measurements were assessed with a 2-week interval by two raters under blinded conditions. Statistical analysis was applied by an independent analyst. RESULTS: The mean SA referenced 142.4 ± 6.9°, PA 5.3 ± 3.8°, LPFA 13 ± 4.4°, and LPL 0.8 ± 2.9 mm. Inter-observer variability showed high correlation for LPL and PA, as the repeatability coefficient was high (LPL; 1.49 (LN), 5.7 (ST) and PA; 4.1 (LN), 5.8 (ST). Also, intra-observer variability showed good correlation for LPL and PA. CONCLUSION: The results represent patellofemoral values in the normal population. They indicate that MRI is a reliable imaging technique to determine lateral patellofemoral length and patellar axis. Lateral patellofemoral angle and sulcus angle showed a poor correlation and should not be used for decision making. LEVEL OF EVIDENCE: Development of diagnostic criteria in a consecutive series of patients and a universally applied "gold" standard, Level II.

A modified tibial tubercle osteotomy for patellar maltracking: results at two years.

An abnormal lateral position of the tibial tuberosity causes distal malalignment of the extensor mechanism of the knee and can lead to lateral tracking of the patella causing anterior knee pain or objective patellar instability, characterised by recurrent dislocation. Computer tomography is used for a precise pre-operative assessment of the tibial tubercle-trochlear groove distance. A distance of more than 15 mm is considered to be pathological and an indication for surgery in symptomatic patients. In a prospective study we performed a subtle transfer of the tibial tuberosity according to the information gained from the pre-operative CT scan. This method was applied to two groups of patients, those with painful lateral tracking of the patella, and those with objective patellar instability. We evaluated the clinical results in 30 patients in each group. The outcome was documented at 3, 12 and 24 months using the Lysholm scale, the Kujala score, and a visual analogue pain score. Post-operatively, all but one patient in the instability group who had a patellar dislocation requiring further surgery reported good improvement with no further subluxation or dislocation. All patients in both groups had a marked improvement in pain and functional score. Two patients sustained a tibial fracture six and seven weeks after surgery. One patient suffered a per-operative fracture of the tibial tubercle which later required further fixation. If carefully performed, this type of transfer of the tibial tubercle appears to be a satisfactory technique for the treatment of patients with an increased tibial tubercle-trochlear groove distance and who present with symptoms related to lateral maltracking of the patella.

[Simple diagnostics of patellofemoral instability point to tailored treatment]. / Eenvoudige diagnostiek leidt tot behandeling op maat van patellofemorale instabiliteit.

Three patients presented with patellar instability. On physical examination, the first patient, a 20-year-old male soccer player, reported pain at the medial insertion ofthe medial patellofemoral ligament (MPFL) after a traumatic patella luxation. He was successfully treated by MPFL reconstruction. The second patient, an 18-year-old woman, presented with patellofemoral pain. On physical examination, the patella could be luxated laterally over approximately half of its width. Conventional X-rays showed a crossing sign, indicating trochlear dysplasia. She was treated by trochleaplasty. The last patient, a 15-year-old girl, presented with patellofemoral instability. On physical examination, a patella alta could be palpated. She was advised to undergo tuberositas distalisation after her epiphyseal growth plates had closed. Patients with patellofemoral instability must be distinguished from patients with patellofemoral-pain syndrome. Simple physical examination and conventional X-rays usually suffice to make this distinction. The treatment is tailored to the pathology found.

Successful total knee arthroplasty in the presence of sporotrichal arthritis.

Articular sporotrichosis, a chronic granulomatous fungal infection, is a rare entity but when present may lead to significant joint destruction. Severe knee arthrosis due to sporotrichal arthritis has traditionally been treated with arthrodesis. Total knee arthroplasty in the presence of sporotrichal arthritis has been treated with long-term suppressive antifungal agents or 1-stage exchange total knee arthroplasty. We present a case in which primary total knee arthroplasty in the presence of sporotrichal arthritis resulted in good functional outcome at 2.5 years of follow-up.

[Small-bowel obstruction as the expression of hereditary non-polyposis colorectal carcinoma]. / Dunnedarmobstructie als uiting van heriditair non-polyposiscolorectaal carcinoom.

A 25-year-old man underwent periodic coloscopy due to the occurrence of colon carcinoma in the family. At the age of 41, a mutation in the MSH2-gene was detected. More than a year after resection of the sigmoid for recurrent diverticulitis, he developed ileus in the small intestine; in the resected specimen of a non-viable portion of small intestine an adenocarcinoma was found. One year after a wide repeat resection, the patient is doing well. The prevalence of small-bowel tumours in patients with hereditary non-polyposis colorectal carcinoma (HNPCC) is relatively high, but low in absolute terms. There are no good options for screening patients for small-bowel tumours. HNPCC patients presenting with complaints that could be due to obstruction should undergo gastroduodenoscopy, coloscopy or, if these yield negative results, wireless capsule endoscopy to reveal obstruction. In case of iron deficiency anaemia or symptoms that cannot immediately be related to an obstruction, one should be careful with a diagnostic laparotomy. In any other case the threshold for a diagnostic laparotomy should be quite low.

Walking, chair rising, and stair climbing after total knee arthroplasty: patellar resurfacing versus nonresurfacing.

During the past decade, the technology and design of knee joint prostheses has progressed considerably. However, there is still much controversy on whether resurfacing the patella during routine total knee arthroplasty (TKA) is necessary. This study compares the biomechanics of the lower limb in patients after TKA with and without patellar resurfacing during level walking, stair climbing, and chair rising. Eighteen patients who underwent TKA by two different surgeons using the same prosthesis were studied after full rehabilitation while walking, stair climbing, and chair rising. Patients were divided between those who were resurfaced and those who were not resurfaced. An aged-matched control population was recruited for comparison. The Hospital for Special Surgery Knee Rating Scale was used to gather clinical information. Kinematic and kinetic parameters were collected using a 5-camera Motion Analysis System and an AMTI OR6-5 force platform. For level walking, patients were asked to walk at a self-selected speed down an 8-m walkway. For stair climbing, patients were asked to climb a 4-step staircase without handrail support and for chair rising, patients were asked to rise from a chair that was positioned at the height of their knee joint line. Five trials for each side were recorded for averaging and statistical analysis. Temporal-spatial parameters and kinematic and kinetic variables at the knee joint were tested for significance using the repeated measures analysis of variance (ANOVA). There were no significant differences in the biomechanics of walking, stair climbing, or chair rising between patients after TKA with and without a resurfaced patella.