A minimally invasive medial patellofemoral ligament arthroscopic reconstruction.

The medial patellofemoral ligament reconstruction is recognized as a good choice for patients with recurrent patellar dislocation. Most techniques of the medial patellofemoral ligament reconstruction are open surgeries. Recently, we present a minimally invasive medial patellofemoral ligament arthroscopic reconstruction technique as a possible alternative method for recurrent patellar dislocation. The aim of the study was to describe a safe and effective technique to perform medial patellofemoral ligament reconstruction. The graft was prepared in shape to "Y." Two 5-mm incisions were made in the skin above the medial edge of the patella. Two docking bone tunnels were drilled from medial edge to the center of the patella, mimicking the wide patellar insertion of the medial patellofemoral ligament, and a bone tunnel was made at the femoral insertion site. Two free ends of the graft were fixed into the patellar tunnels by lateral cortical suspension, and the folded end was fixed into the femoral tunnel by bioabsorbable interference screw. Average patellar tilt and the congruence angle were 30.7° ± 7.5° and 52.7° ± 7.3° and were reduced to 12.8° ± 0.9° and 2.3° ± 11.5° after treatment. The Kujala score was increased from 63.0 ± 9.0 to 91.0 ± 7.0. The minimally invasive medial patellofemoral ligament arthroscopic reconstruction in this paper seems to be helpful to increase safe of operation and treatment effect and reduce complications.

Medial retinaculum plasty versus medial patellofemoral ligament reconstruction for recurrent patellar instability in adults: a randomized controlled trial.

PURPOSE: The purpose of this study was to evaluate the clinical results of medial retinaculum plasty (MRP) and medial patellofemoral ligament reconstruction (MPFLR) with concomitant lateral retinacular release with respect to imaging and functional results. METHODS: Seventy patients with recurrent patellar instability were randomly divided into 2 groups based on their birth years (even/odd), receiving either MRP or MPFLR. Lateral retinacular release was also performed in all patients. Preoperatively, all patients received magnetic resonance imaging to evaluate the injury to the medial patellofemoral ligament. Computed tomography was performed before surgery and at follow-up. The subjective symptoms and functional outcome were evaluated preoperatively and postoperatively with the Kujala score, the Tegner activity score, and a subjective questionnaire. The physical apprehension test was examined, and redislocation was recorded. RESULTS: Patients were followed up for a mean period of 40 months (range, 24 to 55 months). The measurement results for the congruence angle, patellar tilt angle, and patellar lateral shift decreased significantly from the pretreatment measurements to the normal range at the latest follow-up, without a statistically significant difference between the 2 groups (P > .05). The median Kujala score had significantly improved after surgery. However, no statistically significant difference was found between the 2 groups at the latest follow-up (P > .05). In 6 cases in the MRP group (19%) and 3 in the MPFLR group (9%), we found patellar lateral shift that exceeded 1.5 cm but was less than 2.0 cm with a firm endpoint for the apprehension test, without a significant difference between the 2 groups. CONCLUSIONS: This prospective randomized study showed that MPFLR for recurrent patellar instability could achieve good clinical results, with a good congruous patellofemoral joint and good knee function. MRP could yield similar results to MPFLR for recurrent patellar instability in adults with medial patellofemoral ligament injuries from the patella or midsubstance portions. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Double-bundle anatomical versus single-bundle isometric medial patellofemoral ligament reconstruction for patellar dislocation.

PURPOSE: The purpose of this study was to evaluate reconstruction of the medial patellofemoral ligament (MPFL) using the double-bundle anatomical or single-bundle isometric procedure with respect to the patients' clinical outcomes. METHODS: In this retrospective study, we evaluated the clinical outcome of double-bundle anatomical versus single-bundle isometric reconstruction of the MPFL for patellar dislocation patients. Sixty-three patients were included in this study from August 2004 to January 2008. From August 2004 to September 2006, MPFL reconstruction using a single-bundle isometric technique was performed in 21 patients (26 knees). Since October 2006, the double-bundle anatomical reconstruction of the MPFL has been used as the routine surgical procedure. It was performed in 37 patients (44 knees). Fifty-eight patients (70 knees) could be followed up. According to the different techniques, we divided the patients into two groups: group D with double-bundle anatomical reconstruction (37 patients) and group S with single-bundle isometric reconstruction (21 patients). Clinical evaluation consisted of the number with a patellar re-dislocation, patellar apprehension sign, Kujala score, subjective questionnaire score, the patella lateral shift rate and patellar tilt angle measured by cross-sectional CT scan. RESULTS: According to the Kujala score and the subjective questionnaire score, the outcome of the double-bundle group was better than the outcome of the single-bundle group especially in the long-term. Patellar re-dislocation occurred in three patients in the group S, while no re-dislocation occurred in the group D. In total, 26.9 % of group S was considered to have patellar instability, compared to 4.54 % of the group D. After operation, the patellar tilt angle (PTA) and the patella lateral shift rate (PLSR) were restored to the normal range, with statistical significance (P < 0.05) compared to the preoperative state. CONCLUSION: Single- and double-bundle reconstruction of the MPFL can both effectively restore patella stability and improve knee function. However, outcomes in the follow-up period showed that the double-bundle surgery procedure was much better than in single-bundle surgery.

Medial patellar retinaculum plasty versus medial capsule reefing for patellar dislocation in children and adolescents.

INTRODUCTION: The purpose of this study was to evaluate the clinical effect of medial patellar retinaculum plasty for children and adolescent patients with patellar dislocation. MATERIALS AND METHODS: A prospective study was performed between October 2005 and December 2009. Sixty-one cases of children and adolescent patients with patellar dislocation were admitted to our study. Twenty-nine patients received medial capsule reefing, of which 13 patients also received lateral retinacular release (LRR) (Group I). Thirty-two patients received medial patellar retinaculum plasty, of which 12 patients also received LRR (Group II). Preoperatively, all patients received magnetic resonance imaging (MRI) to evaluate the injury of medial patellofemoral ligament. And all patients received computed tomography (CT) scans on which the congruence angle (CA) and patellar lateral shift (PLS) could be evaluated with 30° knee flexion. Physical apprehension tests were examined and the redislocation was recorded. In addition, knee function was evaluated using the Kujala score and subjective questionnaires. RESULTS: Patients were followed up for a mean period of 50 months (25-75 months). For the comparison between the preoperative and postoperative results, the Kujala score improved significantly from 52.3 ± 2.9 to 78.1 ± 3.6 in Group I and from 53.5 ± 3.4 to 82.2 ± 3.4 in Group II (P < 0.05). There was significant difference of CA on CT scans and PLS with a statistical difference between the two groups (P < 0.05). Results of the apprehension test showed that nine patients had patellar lateral shift exceeding 1.5 cm with a soft end point in Group I and two patients had patellar lateral shift exceeding 1.5 cm with a hard end point in Group II (P < 0.05). Moreover, the subjective questionnaire revealed a significant difference of subjective effects between two groups (P < 0.05), including 7 excellent, 10 good and 12 fair in Group I and 18 excellent, 9 good, and 5 fair in Group II. CONCLUSION: The medial retinaculum plasty was better than medial capsule reefing in improving the subjective effects and decreasing the rate of patellar instability postoperatively in children and adolescent patients.

Effect of arginine vasopressin on acupuncture analgesia in the rat.

Arginine vasopressin (AVP) has been proven to be involved in the process of pain regulation. This communication was designed to investigate the effect of AVP on acupuncture analgesia in the rat model. The results showed that intraventricular injection (icv) of AVP could enhance acupuncture analgesia in a dose-dependent manner, whereas icv of anti-AVP serum decreased acupuncture analgesia. However, neither intrathecal (ith) nor intravenous injection (iv) of AVP or anti-AVP serum could influence acupuncture analgesia. Electrical acupuncture of "Zusanli" points (St. 36) decreased AVP concentration in the hypothalamic paraventricular nucleus (PVN), and increased AVP concentration in the hypothalamic supraoptic nucleus (SON), periaqueductial gray (PAG), caudate nucleus (CdN) and raphe magnus nucleus (RMN), but did not change AVP concentration in the pituitary, spinal cord and plasma. The effect of AVP on acupuncture analgesia was partly reversed by pretreatment with naloxone, an opiate receptor antagonist. These data suggested that AVP in the brain played a role in the process of acupuncture analgesia in combination with the endogenous opiate peptide system.

Central oxytocin enhances antinociception in the rat.

The study aimed to investigate the effect of oxytocin on antinociception in the rat. The pain threshold was elevated by oxytocin following intraventricular (icv) or intrathecal injection (ith), and reduced by anti-oxytocin serum (icv or ith). But the pain threshold was not altered by intravenous injection (iv) of oxytocin or anti-oxytocin serum. Pain stimulation induced oxytocin concentration decrease in the hypothalamic supraoptic nucleus, and increase in the locus coeruleus, raphe magnus nucleus, caudate nucleus and spinal cord, but no change in the hypothalamic paraventricular nucleus and plasma. The results indicated that central, not peripheral oxytocin could enhance antinociception.

Effect of oxytocin on acupuncture analgesia in the rat.

Oxytocin has been demonstrated to be involved in pain modulation. Acupuncture analgesia is a very useful clinical tool for pain relief, which has over 2500-year history in China. The present study investigated the role of oxytocin in acupuncture analgesia in the rat through oxytocin administration and measurement. Central administration of oxytocin (intraventricular injection or intrathecal injection) enhanced acupuncture analgesia, while central administration of anti-oxytocin serum weakened acupuncture analgesia in a dose-dependent manner. However, intravenous injection of oxytocin or anti-oxytocin serum did not influence acupuncture analgesia. Electrical acupuncture of "Zusanli" (St. 36) reduced oxytocin concentration in the hypothalamic supraoptic nucleus, and elevated oxytocin concentration in the hypothalamic suprachiasmatic nucleus, hypothalamic ventromedial nucleus, thalamic ventral nucleus, periaqueductal gray, raphe magnus nucleus, caudate nucleus, thoracic spinal cord and lumbar spinal cord, but did not alter oxytocin concentration in the hypothalamic paraventricular nucleus, anterior pituitary, posterior pituitary and plasma. The data suggested that oxytocin in central nervous system rather than in peripheral organs is involved in acupuncture analgesia.

Arginine vasopressin is an important regulator in antinociceptive modulation of hypothalamic paraventricular nucleus in the rat.

Our previous study has proven that hypothalamic paraventricular nucleus (PVN) stimulation increases pain threshold and PVN cauterization decreases pain threshold. The studied neuropeptides in PVN were investigated to involve to pain modulation in the rat. The results showed that (1) intraventricular injection (icv) of anti-arginine vasopressin (AVP) serum completely reversed pain threshold increase induced by l-glutamate sodium (Glu) injection into the PVN, and local administration (icv) of anti-leucine-enkephalin (L-Ek) serum or anti-beta-endorphin (beta-Ep) serum partly attenuated pain threshold increase induced by Glu injection into the PVN, but pre-treatment of anti-oxytocin (OXT), dynorphinA(1-13) (DynA(1-13)), cholecystokinin-like peptide (CCK), neurotensin (NT), corticotrophin-releasing hormone (CRH), adrenocorticotrophin (ACTH), somatostatin (SST), prolactin-releasing hormone (PRH), angiotensinII (AngII), vasoactive intestinal polypeptide (VIP), melanotropin-releasing hormone (MRH), thyrotropin-releasing hormone (TRH), substance P (SP) or growth hormone-releasing hormone (GHRH) serum (icv) did not influence the analgesic effect of PVN administration with Glu; (2) PVN stimulation with Glu elevated the concentrations of AVP, OXT, CCK, NT, CRH, SST, PRH and DynA(1-13) in PVN perfusion liquid, and could not change the concentrations of L-Ek, beta-Ep, AngII, ACTH, VIP, MRH, TRH, SP and GHRH in PVN perfusion liquid; (3) Pain stimulation increased the concentrations of AVP, L-Ek, beta-Ep, DynA(1-13), CRH and ACTH in PVN perfusion liquid, and did not alter the concentrations of OXT, CCK, NT, SST, PRH, AngII, VIP, MRH, TRH, SP and GHRH in PVN perfusion liquid. The data suggested that AVP played a more important role than the other studied peptides (OXT, L-Ek, beta-Ep, DynA(1-13), CCK, NT, CRH, ACTH, SST, PRH, AngII, VIP, MRH, TRH, SP and GHRH) in PVN antinociceptive progress.

Effect of arginine vasopressin in the nucleus raphe magnus on antinociception in the rat.

Previous work has shown that arginine vasopressin (AVP) regulates antinociception through brain nuclei rather than the spinal cord and peripheral organs. The present study investigated the nociceptive effect of AVP in the nucleus raphe magnus (NRM) of the rat. Microinjection of AVP into the NRM increased pain threshold in a dose-dependent manner, while local administration of AVP-receptor antagonist-d(CH2)5Tyr(Et)DAVP decreased the pain threshold. Pain stimulation elevated AVP concentration in the NRM perfuse liquid. NRM pretreatment with AVP-receptor antagonist completely reversed AVP's effect on pain threshold in the NRM. The data suggest that AVP in the NRM is involved in antinociception.

Through the central V2, not V1 receptors influencing the endogenous opiate peptide system, arginine vasopressin, not oxytocin in the hypothalamic paraventricular nucleus involves in the antinociception in the rat.

Our previous study has proven that hypothalamic paraventricular nucleus (PVN) played a role in the antinociception. The central bioactive substances involving in the PVN regulating antinociception were investigated in the rat. The results showed that electrical stimulation of the PVN increased the pain threshold, and L-glutamate sodium injection into the PVN elevated the pain threshold, but the PVN cauterization decreased the pain threshold; pain stimulation raised the arginine vasopressin (AVP), not oxytocin (OXT), leucine-enkephalin (L-Ek), beta-endorphin (beta-Ep) and DynorphinA1-13 (DynA1-13) concentrations in the PVN tissue using micropunch method, heightened AVP, L-Ek, beta-Ep and DynA1-13, not OXT concentrations in the PVN perfuse liquid, and reduced the number of AVP-, not OXT, L-Ek, beta-Ep and DynA1-13-immunoreactive neurons in the PVN especially in the posterior magnocellular part of the PVN using immunocytochemistry. There was a negative relationship between the PVN AVP concentration and the pain threshold; pain stimulation enhanced the AVP, not OXT mRNA expression in the PVN using in situ hybridization and RT-PCR; intraventricular injection of anti-AVP serum completely reversed L-glutamate sodium injection into the PVN-induced antinociception, and administration of naloxone - the opiate peptide antagonist, partly blocked this L-glutamate sodium effect, but anti-OXT serum pretreatment did not influence this L-glutamate sodium effect; L-glutamate sodium injection into the PVN-induced analgesia was inhibited by V2 receptor antagonist - d(CH2)5[D-Ile2, Ile4, Ala-NH2(9)]AVP, not V1 receptor antagonist - d(CH2)5Tyr(Me)AVP. The data suggested that the PVN was limited to the central AVP, not OXT, which was through V2, not V1 receptors influencing the endogenous opiate peptide system, to regulate antinociception.

Arginine vasopressin in the caudate nucleus plays an antinociceptive role in the rat.

Our previous work has shown that arginine vasopressin (AVP) regulates antinociception through brain nuclei rather than the spinal cord and peripheral organs. The present study investigated the nociceptive effect of AVP in the caudate nucleus (CdN) of the rat. Microinjection of AVP into the CdN increased pain threshold in a dose-dependent manner, while local administration of AVP-receptor antagonist-d(CH(2))(5)Tyr(Et)DAVP decreased pain threshold. Pain stimulation elevated AVP concentration in CdN perfuse liquid. CdN pretreatment with AVP-receptor antagonist completely reversed AVP's effect on pain threshold in the CdN. The data suggest that AVP in the CdN is involved in antinociception.

Medial and lateral retinaculum plasty for congenital patellar dislocation due to small patella syndrome.

The objective of this study was to explore the clinical effect of medial and lateral retinaculum plasty for congenital patellar dislocation due to small patella syndrome. Twelve patients with congenital patellar dislocation due to small patella syndrome treated at the authors' hospital between January 2005 and February 2010 were enrolled in the study. The study group comprised 4 men (4 knees) and 8 women (8 knees) with an average age of 10.58±6.91 years. All patients underwent medial and lateral retinaculum plasty. Clinical evaluation included the number of patellar redislocations, patellar apprehension sign, Kujala score, subjective questionnaire score, and patella lateral shift and patellar tilt angle measured using a cross-sectional computed tomography scan. All patients were followed up, and the shortest follow-up time was 2 years. Kujala scores improved from 49.20±6.20 preoperatively to 80.10±5.80 postoperatively. Subjective questionnaire scores indicated that the excellent and good rate was 75%. In addition, a significant difference existed in the patellar tilt angle and patella lateral shift between pre- and postoperative results (P<.05). Medial and lateral retinaculum plasty for patients with congenital patellar dislocation due to small patella syndrome can be effective to correct the tracking of the patellofemoral joint and improve knee function.

Medial patellar retinaculum plasty versus medial capsule reefing for patellar subluxation in adult.

OBJECTIVE: The purpose of this study was to evaluate the clinical and functional results of surgical treatment for patellar subluxation. METHODS: A retrospective study was undertaken between October 2004 and April 2009 of 78 cases of patellar subluxation: 40 cases with medial capsule reefing, of which 15 cases had the combination of lateral retinacular release (Group A); and 38 cases with medial patellar retinaculum plasty, of which 12 cases had the combination of lateral retinacular release (Group B). All patients had CT scans available for reviewing congruence angle (CA) with knee flexion at 30 degrees. In addition, knee function was evaluated using the Kujala score and subjective questionnaires. RESULTS: Patients were followed up for a mean 60 months (33-87 months). The Kujala score improved significantly from 78.3 ± 1.0 to 88.3 ± 1.6 in Group A and from 77.8 ± 0.9 to 91.2 ± 1.7 in Group B (P < 0.05). Postoperatively, the CA on CT scan had a statistical difference between the two groups (P < 0.05). The subjective questionnaire revealed a significant difference (P < 0.05), including 12 excellent, 20 good and eight fair in Group A, and 25 excellent, and 13 good in Group B. CONCLUSION: The medial retinaculum plasty was better than medial capsule reefing in improving the subjective effects and decreasing the patellar subluxation rate.

Endogenous opiate peptides in the spinal cord are involved in the analgesia of hypothalamic paraventricular nucleus in the rat.

Many studies have shown that hypothalamic paraventricular nucleus (PVN) plays a role in pain process, and endogenous opiate peptide system in the spinal cord is involved in nociception. This communication was designed to study the relationship between PVN and endogenous opiate system in the spinal cord in the rat. The results showed that in both the thoracic and the lumber spinal cord, microinjection of 100 ng L-glutamate sodium into PVN could increase leucine-enkephalin (L-Ek), beta-endorphin (beta-Ep), dynorphinA(1-13) (DynA(1-13)) concentrations and PVN cauterization decreased L-Ek and beta-Ep concentrations. Pretreatment of the spinal cord with 5 microg naloxone, an opiate receptor antagonist could partly reverse the analgesia induced by microinjection of 100 ng L-glutamate sodium into PVN. The data suggested that PVN analgesia might be involved in the endogenous opiate peptide system in the spinal cord independently.

[Experimental study of pituitary adenylate cyclase activating polypeptide on relieving brain edema induced by ischemia in rats].

AIM: In order to study the effects of pituitary adenylate cyclase activating polypeptide(PACAP) on brain edema induced by ischemia in rats and its underlying receptor mechanism. METHODS: Brain ischemia model in rats was established by ligaturing four--vessels. The percentage ratio of wet over dry tissue weight, sodium and potassium contents of dry brain tissue were measured by weighing and enzymatic analysis methods. RESULTS: The brain water contents significantly increased after rats exposed to 1 h of reperfusion following 30 - minute ischemia. Furthermore, sodium contents in brain tissue increased and potassium contents decreased following perfusion. Changes of brain water contents, sodium and potassium contents were relieved by lateral ventricular injection of PACAP in the concentration of 1 x 10(-9), 1 x 10(-10) or 1 x 10(-11) mol respectively before ischemia. The effect of PACAP could be blocked by MCAP6 - 38 (specific type I PACAP receptor antagonist) lateral ventricular injection prior to PACAP administration. CONCLUSION: Exogenous PACAP may act as a protective effect in brain edema induced by ischemia in rats, which is mediated by type I receptor.